I am just about completely ignorant of lighting. I have reached out them before and I'll see what they say about this. I appreciate your help and info..i do find it odd that they want you to move a larger light, with 90 more potential watts, closer to the plant than the other. but I am certainly no expert on any of this. just a guy with a couple years experience trying to help troubleshoot :) I just might make a mistake.
**edit** the 350R is a commercial lamp and they are probably factoring in C02 implemented in the grow (if im not mistaken lets you drive the plants harder with feed and light intensity but again i can make a mistake i dont use C02). with that being said they may be giving recommendations based on that and you could reach out to HLG and ask but ive had pretty crappy luck with responses from them, takes a while sometimes and its vague.