ZK-Rollups cannot be implemented in without a hardfork since Miners would have to verify a zero-knowledge proof and miners do not do this in Bitcoin. Bitcoin does have Hash-preimage verification since the very beginning - one could imagine a distributed hash & hash-preimage generation but there is no such algorithm to my knowledge. If there was it would require new and complicated cryptography or a trusted dealer - which both isn't in the spirit of Bitcoin.

Optimistic Rollups are not possible on Bitcoin since they require to undo a transaction in case any party challenges the result. They would also require miners to verify the rollup when someone challenges the result which miners do not do in Bitcoin.

I don't think any of this is a good idea. Rollups always end up with so much chaos that it isn't in the spirit of Bitcoin. And if a construction requires a trusted dealers or a trusted group of participants - why bother with it in the first place - just do it in a SQL database and write the result on the Blockchain.