The fact is (IMO) that the "cutting edge" of audio technology/algorithms/etc is far beyond what a "normie" can achieve. Because here's a simple fact to understand: if it was easy to do, it would have already been done/copied in the DIY/OSS space! What companies like Dirac are doing with ART is far-beyond trial and error. That's why car companies have been paying them big-bucks for their technology/algorithms for years.
Now that's not to say that you cant "help" ART do it's thing, but I can't see how making significant changes to its variables is going to help...
The way to "help" ART (according to my understanding) is to alter the position of the speaker/sub/whatever within the room, because that changes it's " natural in room response" (ie, impulse response), and that new IR might happen to have certain "characteristics" that are better suited for "active cancellation" of problems that other/more-important speakers are having.
And so you're probably thinking "I spent heaps of time in the past getting the sub(s) in to the best position according to [multisub/REW/whatever], so how isn't that the best position for ART?". And that question has a rather simple explanation, which is that you positioned it/them for where their "total" output worked best. And in that context, "total" output is the "source" output (DSP'd or not). What ART is doing is making certain speakers output certain sounds at times that are relevant to the room, not the source (music/movie/whatever). So the "total" of old isn't the same as the "total" of what ART is doing, and hence the speaker/sub might perform better "within the system" when located in a different position.
And I haven't got ART, and so this particular tip is a total guess, but I reckon putting the subs right up against the walls might work best. That's because "every mode" will get "activated" near 100% that way, which means every driver is activating every mode "in time and at max power", which means any driver has its best chance of cancelling a problematic mode from a different driver at the listening position. And if the "theoretical best driver for cancellation" of a particular problem is putting in the majority of the effort to "actively" cancel a particular problem, then I presume that means the end-result will have the best decay/timing and distortion characteristics.