It's a good point you made, to contrast crossovers with room correction filters. They don't have anything to do with each other ideally, except perhaps for sub integration.
The comments I made about less FIR taps sounding better, don't really apply to linear-phase crossovers. Even high order crossovers have relatively low Q's, which don't require a lot of taps to implement. What does take a lot of taps are higher Q PEQ's for example, used to smooth out frequency response. Here's where less FIR is more.....which is no surprise I think, as nearly everyone knows high Q IIR filters tend to suck and are overcorrections.
The potential overcorrection with DRC room correction that goes beyond too much frequency response filtering, is if phase is being altered too. I know Dirac uses mixed phase, having run transfer functions on the filters it generates. No clue about others...but generally, ANY time phase linearization is done other than with complementary crossovers, the potential for pre-ring exists.
The other problem with DRC in my mind, is that although each room mode/reflection itself is minimum phase, the summation of any two together is not....much less all of them together.
That summed hodge-podge is what gets corrected with a single filter set. a ...waay too much luck of the measurement draw for me.
DRC simply has to be to a spot at worst, or to a relatively small area at best.
Personally, I ditched the goal of sweet spot listening over twenty years ago...and has proven to be one of the best audio moves I've made in my life !
