Interesting thread.
I posted about revolver carry awhile ago with a similar thought. I shoot a stock G19 in IDPA. I also carry it quite a lot. My goal is to have fun and get some trigger time with a reasonable gun that I do carry. I'm not concerned about winning as much as competing against myself to show improvement in my skills. That's worked out well.
I've thought about shooting some of my other carry guns just to get some practice with them outside of just the square range. I have a PM-9 but haven't shot it yet at a match. I've seen it done by others.
I've wanted some trigger time with my J frame. At Jim's suggestion, I bought a paddle for it and speed loader carrier. I'm quite aware that if I shoot a 38 SPL snubbie I will come in last unless no one else shows in the revolver class.
However, I want to try it. I'm going to wait however to after the Fiesta Regional match to try this.
I would shoot my regular size gun until I felt comfortable with the IDPA format and then try the PM-9.
Good luck.