I’m sure there’s technical things to consider here. I’d leave it to the app dev to work that out. The point being that removing that choice by default might yield more users.

You’re missing the point. My comment is about induced friction causing people to walk away.

Idk I think the sign up phase could be simpler. A default instance and clear short documentation upon sign up would help. I say this not for me (nerd for 30 years) but just got my partner to switch and they were resistent due to the account creation process. Maybe it’s just the extra dimensions of “picking an instance” but it is a thing and a blocker for engagement.