Everything that uses pre-signed transactions gets improved with CTV. There is nothing complex in understanding this part.

Personally, I would use joinpool: https://gist.github.com/harding/a30864d0315a0cebd7de3732f5bd88f0

I have experimented with the idea on signet and it improves coinjoin. 

 Most things that use pre-signed transactions want to update them (eg lightning), which doesn’t work with CTV.