Absolutely use it and have done so for 20 years. The utility is obvious in theoretical terms, and while exemplary FR is much, much more common now vs then, the fact that there are an ever increasing number of cost no object SOTA systems employing active amplification with DSP would seem to suggest that the old school, passively crossed over loudspeakers are a compromise, and possibly headed for extinction as the younger generation supplants today's well heeled audiophiles (and their typical abhorrence of altering the musical signal).
I don't see DSP as a gimmick any more than a highly computerized F1 race car achieves superior efficiency and fuel efficiency over anything ever built. Once upon a time I viewed tone controls with suspicion, if not disdain--that being the prevailing philosophy of the time, a prejudice even M. Levinson was unable to overcome with his uber expensive "Palette" equalizer.
What I have found to be the case, the better (and typically more expensive) the speaker, the smaller the reward. I see the real sweet spot for performance enhancement to be in the several hundred to several thousand dollar range, with perhaps an ever diminishing difference between a four thousand dollar/pr and forty thousand dollar a pair speakers.
And of course, this is just the speakers--being able to tame bass nodes and ameliorate the more egregious recording/mastering errors are other areas of enormous benefit. I agree that passive efforts to correct room response is always the place to start, but judicious use of EQ can reap additional benefits and/or keep room decor mostly intact as few of us have dedicated spaces. Finally, while ATMOS or some other MCh approach to envelopment is the future, ground breaking work on stereo sound staging has been achieved using head torso transfer function, high DI and sophisticated DSP to minimize the deleterious effect of the wrong channel in the wrong ear errors that degrade 2 channel playback.
Can it be overcooked? Without a doubt, which is one major barrier to wider acceptance and one reason why sales of high end DSP products come with the recommedation of using a trained tech to set up systems.