Basic CRDTs are still useful (idempotency, associativity, and commutativity are powerful mental tools for all distributed systems, even OT) but you can massively simplify the CRDTs if you assume a super-peer (aka centralized server all updates go through).

Example: last-write-wins register, which is a (v, t) pair, normally has a merge function of "return the pair with the greatest t (with deterministic tie breaking for same t)", and for a super peer just have v's and "the latest value to hit the server wins".