Does not help that much....
The reflectors like AAW have a special 98% reflective high durable coating....
The efficiency is only 1.7µmol per Watts.
You profit from HPS if you need the excess heat of it to infrared heat your growing space efficiently. If your climate without any additional heating cost is good, LEDs are far more efficient, no matter if vertical or not, because the reflectors dont reduce the efficiency of the bulbs significantly. Using them without a reflector maybe it's a gain of 3%.... so the HPS in vertical grow might improve from 1.7 to 1,75, thats negligle to what an improvement LED can offer.
Modern LED-modules (LM301H) with Redboost 660nm.... can easily reach 3.5 µmol per Watts (PPE). Thats DOUBLE the efficiency to get the same PAR light. Commercial LED lamps beat at least 2,7 PPE
So like I said, when your ambient/LST is already in good range... a good LED-system are always best and more efficient than any bulb can be! You have more flexibility arrangin LEDs for vert.