Need some advice please (sorry for the long read)...

Back story: I got a 2200 gram normal ball female back in early October who turned out to have a mild RI at the time of picking her up (was fine when we saw her at the previous owner's house but after the transit back up to our house -roughly 2 hour drive- she was popping and wheezing out of the snake bag when we got her home. We believe that the stress from the transit made her RI symptoms become more apparent and that's why we didn't notice anything odd when we went to get her. Took to her vet A to which she was on Baytril injections (.1 cc) every day for 10 days. Her RI symptoms came back after ~a week or so so we did .1 cc of Baytril injections for 30 days which kicked her RI. This vet was not a qualified herp vet (none in our close area).

Fast forward to late January, I noticed her upper right hand side of her mouth was swollen (both the inside near her teeth and the top of her face around her heat pits) so the next day I took her to a new vet, vet B (who sounded to have more experience with snakes, "30+ years," when I talked to the receptionist but not a qualified herp vet). This was January 27th. He recommended a diluted Betadine solution (the medicine is called Chlorehidex on my receipt) swab 3 times a day to the affected area (inside the mouth on that puffy side) for 2 weeks and do a warm compress to the swollen pit area every day as well.

We had to do a swab 2 times a day due to work schedules and stopped the swabs after a week and a half since we had to go out of town for 2 days. When we stopped swabbing after the week and a half her mouth went back to normal (when the swelling was going down we noticed a little red pinpoint dot by her teeth so we think she might have broke one though she hasn't eaten since November 6th). After we stopped the swabbing we checked her mouth two days later and everything looked fine. But after checking a couple days after that we noticed the swelling (both inside and outside her mouth) came back and looked a bit worse than what we noticed on January 26th.

Went back to vet B and he decided to do Baytril injections every 2 days, 3 shots total. He did a full one (1.0) cc of Baytril the first shot and .8 cc for the next two shots. She was looking fine until the morning of shot 3 where the swelling came back even worse than the previous two times. We were advised to still do the swab and compress everyday.

Fast forward to now, the 21st, where she has a checkup on Friday the 24th. So here's where I need some input/advice:

~ Vet B keeps mentioning that she may have built up an immunity/resistance to the Baytril from her previous RI: how easy is it for a snake to become "immune" to a medication or become resistant to it? Could this be the case for my snake even though the first two Baytril shots for her mouth made the swelling go down a lot and it got rid of her first RI?

~ Vet B didn't allow us to do our own injections for her at home: for the 3 shots we had to transport her to their office so the vet tech could do the shots even though we (the bf and I) are capable of doing them ourselves. Is it the norm for vets to not allow their patient's owners to give them their own shots? *Vet A did allow us to do all our own shots at home for her RI once he showed us how to do them.

~ Is a full cc/.8 cc of Baytril a LOT of medication to give in one sitting? Or is this the norm as well? Did vet A do "wrong" to give smaller but more frequent injections to kick her first RI?

~ The vet tech mentioned that if she did build an immunity/resistance to the Baytril that she'd (and quote): "need to be on another antibiotic where she would need fluids every single time" ("every single time" meaning with every shot I'm ASSuming) yet they could not tell me the name of the medication for me to research it myself because "they need to see her again in person". Does anyone know of what antibiotic this might be that they're referring to?

~ They couldn't say what is causing/what caused the swelling (which is hard to say without monitoring her 24/7, I know). What could have caused it? She hasn't eaten since November 6th (a F/T rat) and I haven't seen her rub her face on anything but would just moving around her tub cause a tooth to break/a mild infection to occur?

Any input/suggestions/advice would be wonderful. I hate to come off like I don't trust vet B but there's some things that I'd like to be more enlightened about by being her owner, and an owner of 10+ other snakes (all of which are healthy).

This female is in QT and has been in QT since getting her back in October as well. She is being kept in a tub with a regulated UTH with a plastic water bowl and kitty litter pan hide. Her temps/humidity are spot on and checked with a digital thermometer with hot and cold spots checked with a temp gun.

Thanks