Vaseline is another good substance for soft focus that we used "back when" too.
You might get some slack about leaving the UV filter on while in the studio primarily because you shouldn't be very concerned about ultra violet in such a setting, and adding the extra glass can sometimes cause additional problems with flare, and ghosting. I usually remove any filter when shooting "table top", unless reflections become a problem. Then, I've often used a C-PL instead. If you check with people doing model shoots, you'll find different opinions (like always), but if you leave a filter on full time, be sure and buy the best possible quality. Especially if you're buying expensive glass. I've seen people spend money for "L" glass, then degrade it with a $20.00 filter. I agree it's wonderful protection in general, but not at the cost of photo quality if someone shoots double spread ads for magazines.
If you're only shooting for enjoyment, do whatever works for you. It's when you start looking at others work, and thinking your shots are missing something, that you might decide the extra trouble of adding/removing filters is worth the effort. Otherwise, don't mention it and let the photo speak for it's self. There's times when there's good, and there's good enough. You can't please everyone.. so.. as the song says.