Years ago, when I added and second disk/rotor, I had my "regular" MC bored out to the specs for the one with dual disks and I always felt that the brake lever was a little too hard with not a lot of "feel"
The other day, I bought a used single caliper MC, cleaned it up and put a new seal/piston kit.
Day and night difference,a lot "softer" with much better control.
I remember reading some old tests of the Z (with single caliper) where most of the drivers complained of the effort required and lack of feel and mentionned that adding a second caliper but keeping the single caliper MC, should increase both the braking performance and feel.
They were right.