This recent conversation here is exactly why I've been looking at mDSP and Dirac Live as a solution. Based on everything I can see, the DDRC88A/BM puts that control within reach and the only limiting factor in your set-up is the actual room layout and the channels you can assign through your AVR.
I don't think it is a golden bullet by any means, nor will it be right for everybody in every situation.
But consider that Poes and Shady have much higher opinions about Dirac than any of the other products on the market. You can dial in XOs to the number and slope you choose, so for my 25Hz Phil 3s, If I want to apply a LR4 slope starting only a half octave up at 32.5 Hz, I can.
Instead of buying a $4-5K AVP like the Monolith or Emo, plus all required amp channels (2x Monolithx7 =$3600 or 2x Emo XPA7 =$4200) you can take any of your favorite AVRs that meet your functionality requirements, and add in the necessary mDSP components and run... In my case, an SR6012 at $900, 5x Outlaw 2200 at $1500, and 2xDDRC88A/BM for $2000 and I'd be running at half the cost of those 2 AVP options plus their associated amps. I would not have the ability to assign channels how and where I choose, at least until such a time as I upgrade to another budget friendly AVR. A small price for not spending twice as much!
Regardless, considering the impact of the room and its own unique resonance/Schroeder Frequency on bass performance, then add in the complexities of different equipment including what drivers in what cabinet at what tuning at what roll-off slope... There's a reason even a $20 App doesn't always get it right.
FWIW, I did use the Marantz Graphic EQ to great effect by tuning out a small dip at 2K to tame some borderline fatigue inducing midrange brightness. I think the key is that you need to apply such things minimally and gently and they are not meant to look like the old school mid-'80s component equalizers that people would have maxed at the bass and treble and bottomed out in the mids.
Frankly, that didn't work all that well then.