I can help a little maybe! There's a "Preferences" section called "Followed Hashtags", which is what you want. "Preferences" always seems to open to the "Appearance" section, so it looks like that's all there is, but if you find the right hot-dog-menu thing to click, you can get the menu with all the sections.
@lorihc
Darn wait that's wrong, lol. It's under "Following and Followers" or something like that, which is a *peer* of Preferences, but the only way I know of to get to it is via the Preferences menu. Then under that there's a "Following Hashtags".
Under "Preferences" there's a "Favorite Hashtags" which seems to be... something else.
@ceoln AHA! Found it. So not "Favourite hashtags," but "Follows and subscriptions > Following hashtags.”
@lorihc
Yes! Very obscure. XD
It does seem to work, though.
@ceoln Thank you for your help!
@lorihc
(All of that is in the qoto web interface, which is all I use; in other clients, I dunno!)