Connect for lemmy has account switching and will show you notifications on each account. The annoying part is if you see a post and you want to switch you have to manually find that post again.

I only have 3 (plus an account I only use for development/testing), but I use a client that allows multiple profiles on different instances.

Since reports still don’t federate across instances, I switch to my two alts every so often to check for reports and then switch back to my main.

Uh I just have one alt for doing the five finger shuffle tyvm

You basically never have to login.
The cookie are good for like a year.
Just use… a bookmark?