It worked fine for Tweetbot. Definitely my preference is filtering client side - as the the relay query results are processed.

JB55 has put a lot of effort into making events fetch and render fast. Adding filtering, will have some additional computation. Obviously more filters will mean more non-linear computation. Just need to build it and test really - no point optimising without seeing how a minimal approach goes.

At some point I envision a smarter relay query NIP drafted and can support filters or rules. It’s perhaps a bit early, while what we have largely works ok.