Stock ECU requests more boost for a given IAT (even after density corrections) because you will see significantly less timing with high IATs. So it compensates so the driver has a consistent experience.
When you are running a lot of boost, increasing boost is unlikely to compensate for that.
In general, at very high boost levels, a flat or decreasing KFTARX will get you the most hp over a large range of IAT.
You can, of course, experiment yourself, starting with a flat KFTARX, and see what happens as you IATs go up. With very high IAT, do you get more power with more boost, less timing, or less boost, more timing?
I plan on lots of experimenting for the next few weeks. I just got my car back together yesterday(first start up) its been on jack stands for the past 3 months..I think I have the wrong MAF because the housing has a tube in it so I am looking for a vr6 MAF housing or TT225 and just use the old sensor. It seems the easiest way to go about it. I posted a thread on that but no one has chimed in yet except catbed. I also have some ev14 550's to dial in also. I better do all that first I guess.. I also changed gearing in the trans so I imagine I'll have to play with that also. I haven't read that part of the FR yet..