Right, there are a now lot of different ways to approach amplification.
I happen to be doing a lot of ampless gigs; so, I've actually focused on the pedal board, and then just running that into a power amp When I need a cab on stage. Of course, I can also run into the front end of a traditional head; but, that would be stacking preamps. So, I'm just trying to focus on the pedal board; because I can feed that voicing into either an FOH or a cab via power amp. Juggling different rigs was distracting.
So, it sounds like the Rosette isn't really as appropriate for bass guitar. Still some of those features sure would be nice on the Subway. Boost footswitch and HPF for certain, if we could have those in the Subway footprint. That would be my wish list.
I haven't had an amplified upright gig in a while. When I do, I've actually continued to have the best result running my Underwood into an ART Tube MP, of all things. Amplifying upright is pretty artsy IME. Like you, I gigged a solid body, in my case a Carruthers, for quite a while; but went back to a carved instrument, because I prefer that tone. Amplification for the Carruthers was a whole lot more similar to bass guitar than the Underwood/bass viol. But, for higher volume upright gigs, the solid body instruments are essential. I don't have that covered any more...