What people think of as a gap year can be a little different. Reading what you seem to value, I would just suggest/remind you that you can graduate your year early, apply that summer (which would be your peers' equivalent of applying their junior year, which is totally acceptable), and then do secondaries over the summer, interview throughout fall/winter, and have all the time in between for whatever else you want. Sounds like you are in a position where you don't need to work, etc., so this should be plenty of time for relaxing. I did this, although I graduated in 5 years and applied after graduation (wasn't premed to start), and among my 4 interviews, I was never asked what I was doing in my gap year. In fact, with all the apps they read, my guess is they're probably not paying a ton of attention to remembering your chronology, just the takeaways. And in fact, I DID do scribing, etc., and had to make an effort to bring it up at interviews. By the way, applying is fun, but now that I have been accepted, I am kinda bored even with working full-time and relaxing a lot, and I still have 6 months before school!
I would say there are 3 classes of applicants in regard to when they apply, those: 1) applying junior summer, 2) applying senior summer and thus with a "gap year" (filled by the application process), and 3) those who apply not senior summer, but any subsequent years after that for whatever reasons (and consequently have at least 1 year of technically being able to do "nothing premed" for that whole year, if not more). Of course the latter two groups may be doing x,y,z extracurriculars as opposed to "nothing."
It would be interesting to know what you end up doing; among two friends and myself, we fell into categories 1,2,3 perfectly and although the last hasn't applied, his app will probably be better than mine and I'm anticipating 3/3 of us will have had acceptances first shot. Definitely consider the tier of school you want into, your GPA, MCAT, LoRs, and your narrative for why med and you should get a good understanding of which group you should be in. We each chose our own ways because we had various degrees of unpreparedness paired with chickening out and taking X more years to build our apps before applying
