A thousand users seems like a lot; I'm not sure I've ever been in an IRC room with that many.
Is there a directory? IIRC the human naming part was still missing last time I tried it, and connecting through hashes was not very fun. The biggest blocker for me, though, was the lack of multiple device sync support. A single identity used across multiple devices concurrently is bare minimum feature, and is the reason I've always bounced off SimpleX. Has that been addressed?