The 80-90 psi is the bolt pressure with the Trinity, not the input pressure!
Kind of like you have a cocker which runs at an input of 300psi, but the front reg means the bolt moves back and forth at under 100psi.
The matrix is no different, input is still around the 180psi mark.
Don't ask why I have it - but here is an extract from the Matrix manual
what's the range on each type? I presume if he is running the second reg then the he'll use around a 400psi output from the Max flow and use the secondary reg to go down to 180(ish). So if the high pressure hits around the 400 mark that's right.
but if he wanted to run the MaxFlow straight in, I'm sure he'd need the LP version (which I would say you have yes)