are you looking to hit hte 185 on the Kornit? i think pierre was confused when you called it a press...to most folks here a press spins as you load shirts.
I know the local Kornit shop here had Kornit come in and tweak the settings for a good red.
You won't hit true fluo colors...not with CMYK. It's impossible. You can do bright yellows, and green and such, but they won't be what you can screen print.
Does Kornit pretreat the light colored shirts? If not this is a HUGE obstacle. We pretreat EVERYTHING. Our colors are insanely better. Not just a little, but to the point where I am embarrassed of some of the old work we've done. We use Image Armor light formula...works awesome on poly shirts as well. 5 gallons is about $250.