Oh, I didn't realise it was an approval thing! Geez, there should be an intro tutorial when you get an account there. I've been on years and am still discovering basic stuff. Though I will still say it is a bit clunky.
Maybe like 'orphan work' it can be a tick box option to 'release work' or something? then it can automatically list a required additional tagset and change the connected work settings for that fic alone (so no messing with main account settings or clogging approvals pending lists). I just worry that an additional hub would end up with broken/messy searches and forcing authors to expend more energy on a work they want to drop anyway...