eon, thanks for the further background. I can believe you’ve discovered better performance from where you started. And of course that whets the sonic appetite for more. ;^)
I was not familiar with The Boston Audiophile that MrD suggested. So I went to that site and found this interesting modification for the CW IV. It would be much simpler and less expensive than modifying the crossover.
Note that he also reviews a couple of amps and has a separate link about setup. I’ll just add that I have a Don Sachs line stage and believe he has a good ear and knows what he is doing.