Paste link/username into the search box above the new toot box, hit return, the user will appear in the UI of your home server, hit the ‘follow’ button, done.

Paste link/username into the search box above the new toot box, hit return, the user will appear in the UI of your home server, hit the ‘follow’ button, done. Probably about the same number of clicks, admittedly, but it may feel faster.