First off, I'd like to thank everyone for their feedback so far. Currently, I'm debating doing any cave class this February or none at all. I still plan on getting certified, but haven't decided yet on the path to take to get there. I'm perfectly aware that my plan to be an "infrequent cave diver" is a risk level that many are not comfortable with, but I'm familiar with risk management and plan to do everything necessary to ensure I don't take on any cave diving that I'm not confident is within both my training and my abilities/proficiency at the time I do it (in the future) after I get certified. I recognize some aren't comfortable with that, and that's perfectly fine with me. You're concerns are noted and considered, but at this points I'm set in moving down this path eventually anyway.
So, why the hesitancy to do classes right now? Well, after contacting multiple shops/instructors in the area I plan on vacationing, the paths recommended by them range from "spend 7 days of the 8 day vacation to get some practice/training in doubles and redo the entire cavern course then maybe start intro to cave" to "in ~3 days we'll get you trained up in sidemount (which I've never done at all or considered) AND complete the intro to cave course", ïf you want, "use another 3 days of the vacation and full cave is probably doable as well". The former, taking 5 days to get used to doubles and redo a course I've already done and 2 days starting a course I'd hopefully come back and finish with the same people again if nothing changes in the future to prevent that from happening and I decided to do it in that exact location with the same instructor later and they happened to still be there and doing the courses and I could book into a course when I could get back there, seems like a lot of time and money to make a "relatively" small change and effectively finish my vacation with the same certifications I have with nothing close to a guarantee that it would even be useful in the future for getting the certification(s) I'm working towards, while the latter seems like I'd get the training but would it really be sufficient to make me safe at the level I'd be certified at if I passed everything?
So far, none of the options are looking great/ideal. I don't really want to redo the same class I already did, that "another agency" might call equivalent (or might not, who can tell these days), just because I did it in a different configuration, but I do think getting training/instruction in the new configuration is important. Getting that training/instruction AND doing the class over again just seems like a waste of a money/time with that course however. When talking $250-300/day, redoing a course I've already passed, after doing a course to show I'm competent in the new configuration, seems to be a waste of money. Similarly, change configuration and doing another 3 days course and getting both done in 3-days seems like I'll be missing out on necessary experience/training if I'm that rushed through. So now I'm considering if I want to just have some fun on this vacation, do the tec 40/45 courses I already have booked in backmount doubles, get some experience in them, then go do intro with someone that won't make me redo cavern if I have the doubles experience and cavern cert/experience already at some point in the future.
) etc, I've decided to hold off on getting the next set of training done. Instead I'll go to Cozumel for February's trip, hop over and do a couple days in the Cenotes with some guided cavern diving (checking out a couple different shops preferably) and mostly make this trip about fun. Next year I'm "supposed" to be doing a number of weeks traveling 4 days, which will hopefully get me some 3-day weekends that I may be able to schedule some training in Florida, as well as do my tec 40/45 classes locally in doubles. 
