Changing attribute type in a PersistentCloudKitContainer Model

I have a Multiplatform app using a PersistentCloudKitContainer Model that has a complex object graph and which is still in Development mode (including in CloudKit). An integer attribute of one of the entities needs to be changed to double, for reasons that were not obvious on first analysis of data.

According to the Core Data Migration documentation , which is 10 years old, this case would not be Lightweight Migration and so I would need to create a Migration Policy and Process.

Although I've only recently imported a few legacy records that set the Int attribute (now required to be Double), there are several hundred entities (imported legacy data) with a default Int value (0). Tempting though it is to just change the attribute type from Int to Double and see what happens, recreating the model and hundreds (thousands?) of records if things go wrong would be a real pain in the derriere.

So, given the complexity of my model and the use of CloudKit for multi-device synching, I'm thinking I'll create a new Double attribute and reimport data into that, then when all's fine delete the original Int attribute. This way both sets of changes are Lightweight.

Advice? Thoughts?

Regards, Michaela