I'd watch a Rose show. I mean, I'm not going to subscribe to a streaming service to watch it, but I'd totally watch it if it was on, like, cable.
I'm a little unsure what they could do with Rose, at least as she's set up in TLJ. If they go the mechanic / Resistance fighter, that's kind of close to where "Resistance" is (I think). If they go *after* TLJ, then you've obviously got to deal with Finn - which I would also be interested in (seriously, give me my Finn series) - but that might step on Episode IX: We Ran Out of Titles.
I'd be super interested in a Rose & Her Sister show, because I still feel that aspect of TLJ needed a bit more fleshing out.
A lot of the TLJ subplots suffered because of the need to deal with Luke (which was always going to be the case).