Thanks! I think a unification of OT and CRDT is a very promising space, both for practical implementation and for deeper academic understanding. To be honest, I only skimmed the posted paper, but it didn't grab my attention. It's very difficult these days for me to motivate spending time in this space.

TTF is a CRDT-like approach. They both maintain an extra data structure including tombstones. And TTF-operations are only applied on the designed data structure. To be applied on the document visible to users, TTF-operations need to be translated like CRDT.

Your solution is to combine GOTO with TTF. Actually, it is a combination of OT and CRDT.