Appears to be a minor bug that has affected us from versions 4.0 through 4.2.M2.
When migrating schema using modeler we are repeatedly asked to 'Set Column Type' for a range of columns & types - we can migrate these changes time and again only to be asked to do it again on the next run - specific types;
- BIT -> BOOLEAN (the database already reflects that this is TINYBIT)
- LONGVARBINARY -> BLOB (the database already reflects that this is LONGBLOB)
Screenshot of modeler and part of our schema attached for reference.