Based upon my information from the manufacturer, the pump should be sufficient for 85# injectors, where did your information come from Scott?
I based it in the published flow numbers (chart). Pulling some numbers off the chart, at 70 psi and 13.5 v, the pump supplies about 66 gph. That amount (66 gph) is what 65 #/hr injectors will need at 100% DC, 25 psi boost, and 70 psi total fuel pressure. Or it's also the same amount that 85#/hr injectors at 76% DC and the same conditions require. These numbers assume no system losses, so the actual flow numbers will be somewhat less.
I was unaware the OP had a volt booster.
So with some voltage on the pump it's a better story. At 16 volts and 70 psi total, it looks like it will supply about 84 gph. That's enough for 83#/hr injectors at 100 % DC. Again, this assumes no system losses.
85 #/hr inj is not a stretch as no one runs near 100% DC. But even so, if someone did, a few psi loss is not the end of the world, the inj will still continue to deliver more fuel as %DC increases, just not as much as if the pump were meeting the 1:1 rise.
So the manufacturer told you correct, but only with a volt booster and the associated wiring upgrades. Just can't run 100% DC.