I never really ride in that 100-130 kpa range. The only time that happens is if you lug the car...and then yes it goes rich. Small trade off to deal with if you really want big transients. But the vast majority of the time with a PD blower it tramples through the 100-130 kpa range very fast. I know this is not an ideal way to do this. But it works. At least it worked for me.
I wonder if the 4000 rpm transient shut off has to do with the MAF? I've kind of given up on my MAF tuning because I have so much better consistency and control with my SD/VE tune. And the MV volume seems to be working there for me. Everywhere...including above 4k RPM. Even without a hump in my VE table. In fact I removed this hump and now I'm just letting the transients do their work because I was getting such a huge transient fuel shot at times that I think I was causing some knock because I was too rich. The phenomena of "rich knock". Still don't know if this is a myth or real, but I know once I removed that hump in my VE table the transients tame down a bit and knock decreased.
Anyway. Just throwing some observations and brainstorming here....