diff --git a/mac/Keyman4MacIM/Keyman4MacIM/TextCompatibilityCheck.m b/mac/Keyman4MacIM/Keyman4MacIM/TextCompatibilityCheck.m
index 3797d64864..85932260d8 100644
--- a/mac/Keyman4MacIM/Keyman4MacIM/TextCompatibilityCheck.m
+++ b/mac/Keyman4MacIM/Keyman4MacIM/TextCompatibilityCheck.m
@@ -6,19 +6,28 @@
  * 
  * Created by Shawn Schantz on 2023-05-05.
  * 
- * Check whether the current text input client is compatibility with APIs.
- * Compliance is determined by attempting the current selection (location and length),
- * but this is not a surefire indicator. For some apps,  a valid but incorrect selection of
- * {0, 0} is returned regardless of the real selection.
+ * Check whether the current text input client is compliant with APIs.
+ * Compliance is determined by getting the current selection (location and length) with
+ * the selectionRange API and evaluating the results.
+ * But this is not a surefire indicator. For several apps,  a valid but incorrect selection of
+ * {0, 0}, or possibly something else, is returned regardless of the real selection.
  *
- * When {0, 0} is returned, then we can check to see if a subsequent insert results in a
- * change in the location. It always should, because it cannot replace at location 0.
- * If the location does change, then the selection API is compliant.
+ * When {0, 0} is returned, then we can check to see if a later call to the insertText API
+ * results in a change in the location. It always should, because there is no text to
+ * replace if the client truly is at location 0.
+ * If the location does change, then we assume the selection API is compliant.
  *
- * Even worse for some apps, the selection API works, but attempts
- * to replace during an insert do not work. There is no way to detect this behavior,
- * so these apps must be hard-coded as non-compliant. A couple of known apps
- * that behave this way are Brackets (Adobe OS project) and MacVIM
+ * Even worse for some apps, the selection API returns a non-zero location, but attempts
+ * to replace text during a call to insertText do not function properly. There is no way to
+ * detect this behavior, so these apps must be hard-coded as non-compliant.  A couple
+ * of known apps that behave this way are Brackets (Adobe OS project) and MacVIM
+ *
+ * We really only have the ability to test the selection API, and if it does not work, then
+ * Keyman functionality is limited. Lacking the current location
+ * - we cannot pass a range for reading the context
+ * - we cannot pass a replacement range when calling insertText
+ * The result is that we are limited in key processing, using only locally cached context, and
+ * we can only delete by sending backspace events.
  */
 
 #import "TextCompatibilityCheck.h"
@@ -31,8 +40,6 @@ NSString *const kKMLegacyApps = @"KMLegacyApps";
 @property (readonly) id client;
 @property BOOL apiComplianceUncertain;
 @property BOOL hasCompliantSelectionApi;
-@property (readonly) BOOL hasReadApi;
-@property (readonly) BOOL hasInsertApi;
 
 @end
 
@@ -45,27 +52,17 @@ NSString *const kKMLegacyApps = @"KMLegacyApps";
     _clientApplicationId = appId;
     _apiComplianceUncertain = YES;
     
-    // first check in the noncompliant app lists
-    // TODO: uncomment after testing
-    //BOOL isUncompliantApp = ![self containedInNoncompliantAppLists:clientAppId];
-    BOOL isUncompliantApp = NO;
-    
-    if (isUncompliantApp) {
-      _apiComplianceUncertain = NO;
-      self.hasCompliantSelectionApi = NO;
-    } else {
+    // if we do not have hard-coded noncompliance, then test the app
+    if (![self applyNoncompliantAppLists:appId]) {
       [self testApiCompliance:client];
     }
-    
-    _hasReadApi = [client respondsToSelector:@selector(attributedSubstringFromRange:)];
-    _hasInsertApi = [client respondsToSelector:@selector(insertText:replacementRange:)];
   }
   return self;
 }
 
 -(NSString *)description
 {
-return [NSString stringWithFormat:@"apiComplianceUncertain: %d, hasWorkingSelectionApi: %d, hasReadAPI: %d, hasInsertAPI: %d, canGetSelection: %d, canReadText: %d, canInsertText: %d, canReplaceText: %d, mustBackspaceUsingEvents: %d, clientAppId: %@, client: %@", self.apiComplianceUncertain, self.hasCompliantSelectionApi, self.hasReadApi, self.hasInsertApi, [self canGetSelection], [self canReadText], [self canInsertText], [self canReplaceText], [self mustBackspaceUsingEvents], _clientApplicationId, _client];
+return [NSString stringWithFormat:@"apiComplianceUncertain: %d, hasCompliantSelectionApi: %d, canReadText: %d, canReplaceText: %d, mustBackspaceUsingEvents: %d, clientAppId: %@, client: %@", self.apiComplianceUncertain, self.hasCompliantSelectionApi, [self canReadText], [self canReplaceText], [self mustBackspaceUsingEvents], _clientApplicationId, _client];
 }
 
 /** test to see if the API selectedRange functions properly for the text input client  */
@@ -136,16 +133,22 @@ return [NSString stringWithFormat:@"apiComplianceUncertain: %d, hasWorkingSelect
 }
 
 /**
- * Checks if the client app is known to be non-complian, first by checking the hard-coded non-compliant app list
- * and then by checking the user-managed (via user defaults) non-compliant app list
+ * Apply the hard-coded non-compliant app list and the user-managed (via user defaults) non-compliant app list.
+ * If true, mark the app as non-compliant and certain (not apiComplianceUncertain).
  */
-- (BOOL)containedInNoncompliantAppLists:(NSString *)clientAppId {
+- (BOOL)applyNoncompliantAppLists:(NSString *)clientAppId {
   BOOL isAppNonCompliant = [self containedInHardCodedNoncompliantAppList:clientAppId];
   if (!isAppNonCompliant) {
     isAppNonCompliant = [self containedInUserManagedNoncompliantAppList:clientAppId];
   }
   
   NSLog(@"containedInNoncompliantAppLists: for app %@: %@", clientAppId, isAppNonCompliant?@"yes":@"no");
+  
+  if (isAppNonCompliant) {
+    self.apiComplianceUncertain = NO;
+    self.hasCompliantSelectionApi = NO;
+  }
+  
   return isAppNonCompliant;
 }
 
@@ -157,6 +160,8 @@ return [NSString stringWithFormat:@"apiComplianceUncertain: %d, hasWorkingSelect
     BOOL isAppNonCompliant = ([clientAppId isEqual: @"com.github.atom"] ||
                      [clientAppId isEqual: @"com.collabora.libreoffice-free"] ||
                      [clientAppId isEqual: @"org.libreoffice.script"] ||
+                     [clientAppId isEqual: @"org.vim.MacVim"] ||
+                     [clientAppId isEqual: @"io.brackets.appshell"] ||
                      [clientAppId isEqual: @"com.axosoft.gitkraken"] ||
                      [clientAppId isEqual: @"org.sil.app.builder.scripture.ScriptureAppBuilder"] ||
                      [clientAppId isEqual: @"org.sil.app.builder.reading.ReadingAppBuilder"] ||
@@ -201,53 +206,6 @@ return [NSString stringWithFormat:@"apiComplianceUncertain: %d, hasWorkingSelect
     return isAppNonCompliant;
   }
 
-/**
- * Checks if the client app requires legacy input mode, first by checking the user defaults, if they exist,
- * then, by our hard-coded list.
- */
-/*
-- (BOOL)isClientAppLegacy:(NSString *)clientAppId {
-  BOOL isAppNonCompliant = NO;
-  
-    NSArray *legacyAppsUserDefaults = self.legacyAppsUserDefaults;
-
-    BOOL result = NO;
-
-    if(legacyAppsUserDefaults != nil) {
-        result = [self isClientAppLegacy:clientAppId fromArray:legacyAppsUserDefaults];
-    }
-
-    if(!result) {
-        // TODO: Pages and Keynote (and possibly lots of other undiscovered apps that are otherwise compliant
-        // with Apple's IM framework) have a problem in that if the user selects a different font (or other
-        // formatting) and then types a sequence that causes characters to be added to the document and then
-        // subsequently replaced, the replacement causes the formatting decision to be forgotten. This can be
-        // "fixed" by treating them as legacy apps, but it causes other problems.
-        result = ([clientAppId isEqual: @"com.github.atom"] ||
-            [clientAppId isEqual: @"com.collabora.libreoffice-free"] ||
-            [clientAppId isEqual: @"org.libreoffice.script"] ||
-            [clientAppId isEqual: @"com.axosoft.gitkraken"] ||
-            [clientAppId isEqual: @"org.sil.app.builder.scripture.ScriptureAppBuilder"] ||
-            [clientAppId isEqual: @"org.sil.app.builder.reading.ReadingAppBuilder"] ||
-            [clientAppId isEqual: @"org.sil.app.builder.dictionary.DictionaryAppBuilder"] ||
-            //[clientAppId isEqual: @"com.microsoft.Word"] || // 2020-11-24[mcd]: Appears to work well in Word 16.43, disable legacy by default
-            [clientAppId isEqual: @"org.openoffice.script"] ||
-            [clientAppId isEqual: @"com.adobe.illustrator"] ||
-            [clientAppId isEqual: @"com.adobe.InDesign"] ||
-            [clientAppId isEqual: @"com.adobe.Photoshop"] ||
-            [clientAppId isEqual: @"com.adobe.AfterEffects"] ||
-            [clientAppId isEqual: @"com.microsoft.VSCode"] ||
-            [clientAppId isEqual: @"com.google.Chrome"] ||
-            [clientAppId hasPrefix: @"net.java"] ||
-            [clientAppId isEqual: @"com.Keyman.test.legacyInput"]
-            //||[clientAppId isEqual: @"ro.sync.exml.Oxygen"] - Oxygen has worse problems
-        );
-    }
-
-    return result;
-}
-*/
-
 /**
  * Checks array for a list of possible regexes to match a client app id
  */
@@ -275,25 +233,16 @@ return [NSString stringWithFormat:@"apiComplianceUncertain: %d, hasWorkingSelect
   return self.apiComplianceUncertain;
 }
 
-
--(BOOL) canGetSelection {
-  return self.hasCompliantSelectionApi;
-}
-
 -(BOOL) canReadText {
   // seems simple, but every application tested that returned the selection also successfully read the text using attributedSubstringFromRange
-  BOOL canReadText =  self.hasReadApi && self.canGetSelection;
-  return canReadText;
-}
-
--(BOOL) canInsertText {
-  // all applications tested can insertText (though replacement may not work)
-  return self.hasInsertApi;
+  
+  BOOL hasReadApi = [self.client respondsToSelector:@selector(attributedSubstringFromRange:)];
+  return hasReadApi && self.hasCompliantSelectionApi;
 }
 
 -(BOOL) canReplaceText {
   // testing shows that every application that returns the selection, can also replace text
-  return self.hasInsertApi && self.canGetSelection;
+  return self.hasCompliantSelectionApi;
 }
 
 -(BOOL) mustBackspaceUsingEvents {
@@ -301,43 +250,4 @@ return [NSString stringWithFormat:@"apiComplianceUncertain: %d, hasWorkingSelect
   return !self.canReplaceText;
 }
 
-/*
--(void) experiment {
-  NSRange notFoundRange = NSMakeRange(NSNotFound, NSNotFound);
-  NSRange zeroRange = NSMakeRange(0, 0);
-  NSRange selectionRange = [self.client selectedRange];
-
-  if (NSEqualRanges(selectionRange, notFoundRange)) {
-    NSLog(@"**compatibility** ERROR selectedRange = {NSNotFound, NSNotFound}");
-  } else if (NSEqualRanges(selectionRange, notFoundRange)) {
-      NSLog(@"**compatibility** ERROR selectedRange = {0,0}");
-  } else {
-    NSLog(@"**compatibility** selectedRange = %@", NSStringFromRange(selectionRange));
-  }
-  
-  NSRange contextRange = NSMakeRange(1, 0);
-  NSLog(@"**compatibility** get string of empty range, location 1, length 0");
-  
-  NSAttributedString *attributedText = [self.client attributedSubstringFromRange:contextRange];
-
-  if (attributedText == nil) {
-    NSLog(@"  **compatibility** attributedSubstringFromRange({1,0}) is nil");
-  } else {
-    NSString *context = attributedText.string;
-    NSLog(@"  **compatibility** attributedSubstringFromRange = %@", context);
-  }
-
-  contextRange = NSMakeRange(1, 1);
-  NSLog(@"**compatibility** get string at location 1, length 1");
-  
-  attributedText = [self.client attributedSubstringFromRange:contextRange];
-
-  if (attributedText == nil) {
-    NSLog(@"  **compatibility** attributedSubstringFromRange({1,1}) is nil");
-  } else {
-    NSString *context = attributedText.string;
-    NSLog(@"  **compatibility** attributedSubstringFromRange = %@", context);
-  }
-}
-*/
 @end