I don't have direct experience with that flow yet. Once the new systems are up and running, I'll devote some time to experimenting with it.
I doubt that there will be a problem with it, as long as you keep the wand moving. The main thing will be to not let the spray "puddle" under the jets.
Sure, if you bounce the spray off of the wand lips or
glides, you have less impact and less chance to puddle... but impact is a good part of what it's all about, in the final analysis, regarding flow rate.
As far as a system being, "properly made", I know I have that covered with regard to vacuum, with a couple of new tweaks I've put in.
I'll be curious to see how the heat holds up at that rate, though.
The thing is, that a standard should be developed. (I posted about this years and years (it seems) ago, on the CleanFax board when it was, "the" board.
The standard really should be based upon GPM... not "PSI" (it varies with hose length, hose size, as well as jet size), or jet size alone.