I am just concerned that the ADA conversion will loose the original SQ.
There are TONS of variables involved in this question. I’d say do what you can with room treatments and then give some form of good DSP a try and see how it works in your room and system. I’ve heard RC work in expensive systems that made such a dramatic improvement it swamped any concerns about the additional digital processing, but that was just in that instance but demonstrates the level potential benefit. I’d say try to demo something like a DSpeaker anti-mode 2.0 (or buy one used) and just see what you think. It’s really the only way to know, but I will say I think it’s WELL worth your effort to try. Best of luck.