You should see some threads linked on github-drama, there were >1000 comments when audacity tried to add telemetry.

Also new to Lemmy, but it looks like it only really matters which instance you register with if the instance shuts down (your account will be lost).

You should also try to pick a smaller instance, to avoid unneccessary load on the few ‘main’ ones, but also make sure you’re on a reliable instance, since you’ll lose access to Lemmy in downtime.

Also, when communicating with other instances, they can see the one you signed up to (I’m on sh.itjust.works).