Even more, make it more like a backup feature that's opt out not opt in. Thus, when a server goes away, the user still has their community list to import somewhere else.

Came here with the same idea. The ability to sync a selection of subscriptions between different accounts would be a fantastic extension to this feature.

While lemmy.world was experiencing issues with the recent vulnerability I signed up a 2nd account with a different instance. Not having the subscriptions from lemmy.world is a pain, especially after the last few days of collecting subs.