I'll be honest - once you get used to flats and what you can do with them, it's going to be very tough to switch to rounds and instantly have a wow moment playing the genre that you do. I just wrapped a neo soul record and used a Pbass with flats (AVRI) and it just sounds so much better than with rounds. If you are into a warm, thick tone that still has heavy focus, it's just unbeatable. Hell, I even take jazz/fusion solos and it kills. I had rounds on the same Pbass and it was still great, but not nearly as special.
It is possible that you may need to demo new basses with flats, and least to start. It's too much of a change to go to a new bass and new strings sometimes.