What's the intended workflow to migrate C++/Blueprint files?

We’d like to transfer some files from one project to another one. Migrating works fine for (Blueprint) assets, but we’re facing a lot of problems whenever we try to move Blueprints whose parent is a custom C++ class.

AFAIK, source files can’t be migrated but when copying them into the project manually, the parent connection gets lost. This will often cause the editor to crash. Even when this is not the case, all references need to be fixed manually.

What’s the intended workflow for this?

Haven’t heard of any recommended migrating path. Had problems with migrating materials loosing their material function references. May be it is better to migrate C++ classes first. And than try to migrate their blueprints. Still there is possibility for UE to crash and manual blueprint reparenting.

Don’t think things changed too much from a 4.8 version.