Anyone off hand know what distance the light should be during flowering from the tops of the girls? I have the R-Spec 260 watt qb from Grower’s Lights. Thanks! 
I have no experience with that light, but I would say keep it the same distance as you had it in veg…
How big is the grow space and which kit is it? I would say you don’t want it any closer than like 15-16". Maybe higher if you need more coverage
Horticulture Lighting Group 260 Watt Quantum Board LED Kit V2 Rspec. I have it at about 14 inches right now. The flowering area is roughly 2’ x 3’, maybe 3.5’.