diff --git a/ios/engine/KMEI/KeymanEngine/Classes/Manager.swift b/ios/engine/KMEI/KeymanEngine/Classes/Manager.swift
index 1a79eab4a4..bd2af0e969 100644
--- a/ios/engine/KMEI/KeymanEngine/Classes/Manager.swift
+++ b/ios/engine/KMEI/KeymanEngine/Classes/Manager.swift
@@ -344,7 +344,24 @@ public class Manager: NSObject, UIGestureRecognizerDelegate {
   /// The keyboard must be downloaded (see `downloadKeyboard()`) or preloaded (see `preloadLanguageFile()`)
   @available(*, deprecated, message: "Deprecated in favor of ResourceFileManager.install(resourceWithID:from:)")
   public func addKeyboard(_ keyboard: InstallableKeyboard) {
-    ResourceFileManager.shared.addResource(keyboard)
+    var kbdToInstall = keyboard
+
+    // 3rd party installation of keyboards (13.0 and before):
+    // - Manager.shared.preloadFiles was called first to import the file resources
+    // - Then Manager.shared.addKeyboard installs the keyboard.
+    //
+    // Since 3rd-party uses never provided kmp.json files, we need to instant-migrate
+    // them here.
+    if !Migrations.resourceHasPackageMetadata(keyboard) {
+      let wrappedKbds = Migrations.migrateToKMPFormat([keyboard])
+      guard wrappedKbds.count == 1 else {
+        log.error("Could not properly import keyboard")
+        return
+      }
+      kbdToInstall = wrappedKbds[0]
+    } else {
+      ResourceFileManager.shared.addResource(kbdToInstall)
+    }
   }
     
     
@@ -391,7 +408,24 @@ public class Manager: NSObject, UIGestureRecognizerDelegate {
   */
   @available(*, deprecated, message: "Deprecated in favor of ResourceFileManager.install(resourceWithID:from:)")
   static public func addLexicalModel(_ lexicalModel: InstallableLexicalModel) {
-    ResourceFileManager.shared.addResource(lexicalModel)
+    var modelToInstall = lexicalModel
+
+    // Potential 3rd party installation of lexical models (12.0, 13.0):
+    // - Manager.shared.preloadFiles was called first to import the file resources
+    // - Then Manager.addLexicalModel installs the lexical model.
+    //
+    // Since 3rd-party uses never provided kmp.json files, we need to instant-migrate
+    // them here.
+    if !Migrations.resourceHasPackageMetadata(lexicalModel) {
+      let wrappedModels = Migrations.migrateToKMPFormat([lexicalModel])
+      guard wrappedModels.count == 1 else {
+        log.error("Could not properly import lexical model")
+        return
+      }
+      modelToInstall = wrappedModels[0]
+    } else {
+      ResourceFileManager.shared.addResource(modelToInstall)
+    }
   }
 
   /// Removes a keyboard from the list in the keyboard picker if it exists.
diff --git a/ios/engine/KMEI/KeymanEngine/Classes/Migrations.swift b/ios/engine/KMEI/KeymanEngine/Classes/Migrations.swift
index 6d4dc0a850..d5fc6706d5 100644
--- a/ios/engine/KMEI/KeymanEngine/Classes/Migrations.swift
+++ b/ios/engine/KMEI/KeymanEngine/Classes/Migrations.swift
@@ -698,4 +698,10 @@ public enum Migrations {
 
     return matched + mappedResources
   }
+
+  internal static func resourceHasPackageMetadata<Resource: LanguageResource>(_ resource: Resource) -> Bool {
+    var resourceDir = Storage.active.resourceDir(for: resource)!
+    resourceDir.appendPathComponent("kmp.json")
+    return FileManager.default.fileExists(atPath: resourceDir.path)
+  }
 }
diff --git a/ios/engine/KMEI/KeymanEngine/Classes/Resource Management/ResourceFileManager.swift b/ios/engine/KMEI/KeymanEngine/Classes/Resource Management/ResourceFileManager.swift
index 26f5cf9982..6a72f23916 100644
--- a/ios/engine/KMEI/KeymanEngine/Classes/Resource Management/ResourceFileManager.swift	
+++ b/ios/engine/KMEI/KeymanEngine/Classes/Resource Management/ResourceFileManager.swift	
@@ -217,6 +217,12 @@ public class ResourceFileManager {
     }
   }
 
+  /**
+   * Searches the specified package for a language resource with the indicated resource-language-code "full ID" key,
+   * importing the package's files and installing the indicated resource-language pairing upon success.
+   *
+   * The`resourcesWithIDs:` variant is better optimized for installing multiple resources from the same package.
+   */
   public func install<ResourceType: LanguageResource,
                       PackageType: TypedKeymanPackage<ResourceType>> (
                         resourceWithID fullID: ResourceType.FullID,
@@ -225,6 +231,10 @@ public class ResourceFileManager {
     try install(resourcesWithIDs: [fullID], from: package)
   }
 
+  /**
+   * Searches the specified package for language resources with the indicated resource-language-code "full ID" keys
+   * importing the package's files and installing the indicated resource-language pairings upon success.
+   */
   public func install<Resource: LanguageResource,
                       Package: TypedKeymanPackage<Resource>> (
                         resourcesWithIDs fullIDs: [Resource.FullID], from package: Package) throws {