Is your goal to have a significant portion of your career be related to obtaining grants and doing research? Running your own lab? It sounds like you are not already significantly involved in research. It might make more sense to start residency, build connections with productive researchers, and do a masters or phd at your next institution if that is the goal. You likely need a higher level of training around research itself to build out this portion of a career. I'm not a researcher so take this with a grain of salt, but this is what I've seen in academic when people are trying to build research careers (keep in mind most of them burn out of this track and end up as regular clinicians or clinician-educators)
If you are not planning on a career in research, I don't think this is a great use of your time. I considered doing what you are thinking about (was going to work on a research project in LA about psychiatric outcomes in jails) but was convinced by my med school department chair it would not be a great use of my time. It likely won't make you significantly more competitive for the highest tier residencies, unless your output is extremely productive (unlikely in a year in a brand new place). I ended up just applying to residencies on the normal schedule and am very happy that I did so. It would have been a mistake, in retrospect. I assumed I was headed for an academic career (and did residency/fellowship at academic programs) but figured out along the way this was not what I'm interested in.
If you're feeling super burnt out from school and need a break, then this changes the equation.