The app that synchronizes multiple lemmy accounts so you can migrate and keep backup accounts across instances, it's opensource and free, currently working in android and windows.
It's in homologation now and anyone can test, any feedbacks are welcome as always.
Connect is a client, it shows Lemmy content and let you interact with them
Handshake is an account synchronizer, it syncs multiple accounts so you can keep accounts across instances with the same communities and soon saved and banned content
How are you gonna implement saved/banned content replication? Alls ids for posts are local to that instance, how are going to find one post from on instance in another. It might not even exist yet.
? You can't use the same strategy for what u do to find communities. (assuming you use the name field to retrieve the community) there is no equivalent
In case you're still wondering. This app can take all your subscriptions from lemm.ee and copy them to another instance. When you switch to that instance and go to your subscribed everything should be on the second instance.
This way you don't have to subscribe manually on multiple instances. I believe blocks will be added as well.
This app would have done step 4 without you having to do it yourself.
As for why to switch instances. It's a matter of preference. The example you gave is a good reason. Obviously if your instance closes you would have to move so it's nice to have a backup just in case