I'm curious about the idle quality statement? Why would idle
That was my experience. I tried fixed timing, but tough to crank, even backfiring. I tried using 12 degrees of mechanical advance but had to set the total advance based on the second stage maximum timing.
When I finanly went to muli stage box, I could idle at lower RPM and reduce timing when stages kicked in.
Disclamer: This was several years ago and technology has tried to pass me by several times. After watching the pro teams, I am guessing you can do anything with timing with enough money. Just my experience...