it should be the height that best covers the area and hopefully enough power at that height to provide "max" DLI relative to environment.
it may slow down, but you definitely have a couple weeks of vege growth remaining (leaves and stem elongation).
if you don't singe pistils or bleach buds, you are fine at 10 inches. this sort of damage can sometimes take weeks to present itself from onset of problem. so keep notes of power and distance... observe plant and react when necessary. too tight node spacing, you probably need less light. too stretchy and you probably need more. So, observe what little vege growth remains as it will help avoid issues in late flower.
buned pistils will look like little yellow nubs
200 w in a roughyl 2x2 foot area is a bit overpowered, so i'd becareful at 10". i'd guess that will eventually show some light damage, even if not in first few days.
460 umol/s / .36m^2 = 1200some PPFD. over 18 hours that's potentially WAY too much light. you'd be good with a 12/12 cycle at 18" and 100% power, in that tent, i bet. So with autoflowers, you'll need less over 18-20 hours -- proportionally less relative to hours of use.
so, do what you gotta do, but any hint of light issues (damage or even just really droopy plants last hour or more of light cycle) and be ready to dial it back a bit. either more height or reduce power. both can work.