I don't know about topping at night vs. daytime... I thinks with your extended veg time topping would be very doable for you, my girls literally just barely fork out before they hit 12/12 and I generally end up with 4 nice tops and a nice full middle(I spread the 4 tops out on a hoop). So what do you do? LST? Supercrop?
I don't use smartpots, I tried them in the past and I just did not like them. I can't remember why, because in my head they seem like a great idea, but they did not work for me.
Anyway I checked out that link. Great website in general... It seems like a pretty cool idea, I'm going to make one today and do a side-by-side and see how much of a difference it makes... As far as how he does it without pipe, he's just drilling a hole through the side and watering with a watering can through that hole- your way sounds a lot more efficient and convenient. I can see tea getting nasty in that space, but when I use a tea I usually have barely any leakage, I'm cheap!