Excellent, the fog of information is clearing! Now onto the horsepower topic! I have 40cm2 / 16in2 floor, is a 50W COB or 65W QB appropriate? Both have up-rated versions: Optic 1XL (100W) and HLG 100W. More light = greater yield or just overkill for extra purchase & electricity cost. I'm new to this and aware I can burn the plants with too much light. Don't want a light that is to powerful, because I just need to replace it!
Since neither have dimming, I'd stay with the lower wattage, especially for veg.
Having said that, there are ways to reduce power or add dimming, but that's another topic.