I find your project a very powerful feature which should be default into GO Lang.
There's one feature which could be implemented and make others life a lot easy. In the past the PC COBOL had a feature called "MOVE CORRESPONDING ...". Which was used to move values between structres fields with the same name. Ignoring the not corresponding.
I guess your package could implement it. Allowing to move field values between structs with fields of same name and type.
Anyway, thank you for your work.