I'm far from an expert in lighting but I think your PPFD is what is going to matter when it comes to canoeing, not DLI. I stand to be corrected as I am making an educated guess.Yeah I think I'm gonna decide to stop worrying.
I do want a little uv light, or maybe one to grow in the tent.
The big ganesha curtain on the front of the tent is uv reactive, also good to keep away certain pests & fungi.
With the flash everything is very green as with regular light.
I still get a lot of canoeing on top though, and dimming the light is not really an option with it being so high.
I've been thinking maybe snip a few light hours off so they got more time to relax.