Merge pull request #10091 from mauritselzinga-mx/patch-36

Update dev-best-practices.md

Author: Yiyun333

content/en/docs/refguide/modeling/dev-best-practices.md

@@ -352,6 +352,12 @@ Applications exceeding these guidelines may still function, depending on your sy
 Project size impacts IDE performance. Choose a development strategy that aligns with your system's capabilities and Mendix's recommended guidelines.
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+### Model SDK
+
+The Mendix Model SDK enforces a strict limit of 20,000 units per working copy.
+  
+A unit represents a single document or element found in the app explorer. This limit helps ensure stable performance and efficient resource handling when working with large Mendix applications and models through the SDK. When building solutions or automation using the Model SDK, ensure that working copies do not exceed the 20,000-unit threshold to avoid errors or incomplete processing.
+
 ### Domain Models
 
 #### Attributes {#attributes}