For those two specifically I’d suggest to host one yourself. You then are 100% in control over blocking users/instances and the latency is super short because you’re the only one on the server. That’s what I’m doing.
I self-host my own Mastodon server and relay about 50 hashtags (no full servers). Even with media getting flushed every 3 days, it still hovers around 20GB.
I’m probably gonna do it now, because of course I will.