I think I usually use nostrcheck.me or nostr.build I would have thought one of them does bloom filters and I'm sure I've used void.cat and maybe blossm.band before too in the past. Just not sure what retention is like and this is all just from spotty memory, I'm happy to accept that I have never used a blossom server but it definitely doesn't sound like me to not play with one when I heard about it way back when.