'12 zl1

I added an aux pump and it works great, except it spikes fuel pressure to 85psi until I'm over 5000rpm and IDC is high enough to bring it back down to 70 or so. This makes maf/vve calibration a little wonky, and the rich spike (9.5:1 at times) is also giving me a bit of tiny knock even with the timing pulled for the maf/vve calibration.

For now, with my limited knowledge of how the ecu and/or fpcm controls the pump, I'm assuming it just cuts voltage and duty cycle for the pump to attempt to bring FP back to the commanded 65psi for high flow. Can I lower the minimum duty cycle in the tune from 10% to 5% to help, or is that too low? Will it help at all?