if u add more lumens from either cool white(6500k) or warm white(2700k) it will help the plant grow / flower .
in general speaking , more lumens at the right spectrum = more grow .
BUT , for grow u would want a more blue'ish spectrum (cool white) ,it will affect better .
and for flowering u would want a more red - yellow spectrum (warm white) .
for optmial usage , u can use mix spectrums . 70% - 30% . it will help simulate the sun light . as the sun light is white light (all spectrums) .
for grow , 70% blue , 30% red -yellow.
for flowering , 70% yellow - red , 30% blue .