I've learned the hard way it's impossible to diagnose issues sight unseen over the web. The clearances you cite are VERY high, and the fact it took a heat-press to get there is concerning. This would tend to tell me the bass was not maintained with regular adjustments in its time before it got to you, and your tech felt this is what it would need to 'reel it back in'.
My method was a general 'field maintenance' for regular player axes in relatively good shape: No huge fret ruts or high frets, no big twist or deep relief, etc. The numbers I quote were a basic starter set, with the imprimatur to take them as a starting point to find your own personal setup numbers. There's a lot of BS out there, and my thought was to put setup method in terms of repeatable numbers, the same way the manufacturers and good techs do it. But it's for axes in the state I mentioned, and is NO replacement for a qualified tech for more serious concerns that this can't address.
I'd think a bass that required a heat-press would be outside of that situation, IF you're dealing with a qualified repair person. I'd be surprised if with a heat press, the neck could not be brought to a dead-straight relief state with the strings off, the frets leveled and re-crowned if required, then re-strung and set to suit. However I can easily see where the neck through would make it far more difficult to get all the neck as opposed to say, a Fender neck that can be removed completely. But again, this bass is not in front of me, nor do I know the experience and rep of your repair person. Sometimes, a guitar or bass is just not going to come back, time and wood have had their way too long to be brought back but it's rare.
Generally a 'neck reset' is referring to acoustics or electric guitars with a glued-in neck: The neck joint is generally warmed or steamed to loosen the glue, then you pull the neck out of the dovetail joint. This is not uncommon on some acoustics where you've run out of bridge saddle height and the neck angle needs to increase slightly, the same idea as shimming a Fender-type screw-on neck. You do some slight sanding on the tenon on the neck to lower the head end slightly, glue and reset, and now you have more 'maneuvering room' at the saddle or bridge, and you're on your way.
Heat Treatment on the other hand is taking the neck (either removed or in place on a neck-through), supporting the neck at both ends, then applying a heated bar to the fingerboard/ frets with a strategically-placed vice to push the neck straight with the truss rod relaxed. After a certain period of time, you kill the heat, leave everything vised up until everything comes back to room temp. IF everything went as hoped (it doesn't always . . . .), it will now stay straight, level the frets if necessary, then re-install, re-string, and the string load will introduce some relief that hopefully now the truss rod can bring to just right.
Again, I'm not there, but I'd continue to work with your tech to resolve this, or if necessary, get a 2nd opinion.