Compatible versions are determined by matching version numbers.
Solve by doing exactly what you propose. Pull the binary, revert your changes, version the model, remake your changes, ensure that auto-migration is enabled and test that it works correctly.
The version number is created by generating a 32-byte hash digest of the components which are compared for equality:
For each entity the following attributes must be equal: name, parent, isAbstract, and properties. className, userInfo, and validation predicates are not compared.
For each property in each entity, the following attributes must be equal: name, isOptional, isTransient, isReadOnly, for attributes attributeType, and for relationships destinationEntity, minCount, maxCount, deleteRule, and inverseRelationship. userInfo and validation predicates are not compared.
Technically, if you don't change anything that doesn't affect the version number then you don't need to version the model. Note that your change will impact the version number so you do need to take action.