Those plants look incredibly healthy! I see practically no purple in the leaf stems/petioles at all. I see this very rarely these days.
Are you under solely LEDs? I'd really like to hear your thoughts or impressions on this purple-ing of the leaf stems, like if you used to get them, and what changes you made (nutrient, environment, lighting aspects, etc.) and what you've noticed.
Did you drill your own holes in the sides of those pin heatsinks? I don't remember seeing screw holes that far apart.
Thanks for any insight.