not saying i follow everything you just said (i cant read a compressor map to save my life - never bothered trying), but i think any 9 year old can tell you 400hp from 15psi is going to be better than 400hp from 30psi, stress-wise.
dunno, but i DO know a few miata guys running the gt28rls at psi in the 20s. theyre getting 250-300rwhp (they also have bigger motors than half a z does). th e'l' in the middle is supposed to mean its a .6x a/r instead of the .8x of the rs you guys are talking about. did that make any sense? or add anything? no? sorry