Prior to switching over to the Sandbox framework for semantic model extensions, note the tasks and ensure to take appropriate action where required in the suggested sequence.

Begin by migrating the non-production instances to the Sandbox framework before migrating the production instance. If you've multiple instances such as development, stage, and production, prepare a semantic model extensions migration timeline for each instance. After the initial instance is migrated, it isn't possible to bundle the semantic model extensions until the target instance is on the same semantic model extension framework. It's recommended to complete the migration of the production instance promptly after migrating the lower instances to avoid bundle delays.