I was about to give 2/5 because I thought this addon no longer worked however, I was redirecting to elk.zone and putting in different instances to redirect too, I realise that it is Elk that seem to have changed something that has killed the addon.
This addon can still redirect any account to elk.zone however, you get /authorize_interaction?uri= when redirecting from posts now.

It just redirects links to accounts on other instances. Super simple and EXACTLY what I was looking for.

Edit: stopped working for some reason, now it just reloads the page over and over. Yes, I am logged in to my instance and the addon has worked before.