Most cave instructors expect you to have perfected trim/buoyancy and fin technique before attempting the course. Novice divers can be discouraged if thrown in the deep end.I think doing the first half of cave training in Florida and the second half in Mexico has some advantages.
The first half of cave training is about learning how to handle a reel, tie into the line, perfecting techniques (buoyancy, kicks) and get in and out of the cave safely. You don't need to log 80 minute dives at this level, ~30-40 minute dives are more than ample to develop the skills necessary to progress, and you can easily do that while staying within NDL's even in our deeper systems. Florida will challenge your reel/line work due to the flow in ways you'll never get in Mexico, if you can learn to run a reel in Florida, you'll be good in most other places.
The second half of cave training is about perfecting your skills while adding navigation, complex gas planning, circuits and traverses. Longer bottom times at this level are really really important, so are opportunities to experience navigation. Mexico is the place for this.