I realize many are opposed to implement some sort of DSP into their system but it may be the best/easiest/most cost effective solution if you haven’t tried yet. Even more so if there are trying to optimize/integrate subwoofers.
Having the ability to easily adjust sub/mains x-over pts., phase, gain, along with eq from your listening chair can be a game changer if your end goal is suspension of disbelief rather than to micro analyze and meet some undefinable, unobtainable true to “what the musicians, or engineer intended” type objective.
From what you describe as missing I sense that you’re not after that illusive moving target so I’ll just reiterate my recommendation to try DSP (if you haven’t yet).
I feel liberated after many years of struggling to be transported from my listening chair to the “event” and I think MG 3.7i can get you there with DSP.
edit..
assuming 3.7’s are setup properly…at least 5-6 ft. from front wall and seating position not up against back wall. Minimum 14ft room width. Light room treatment, smartly placed.