Scrog, net and timing

best time would be right before you flip your light to flower - you plants will get a boost when entering the flowering stage. best of luck 🌱💚

How are you going to use it? if it's just for support, you need it maybe 3 weeks into flower? Around the time it's vertical height is about half as tall as it will get. Some scrogs are used for training too, and that would be needed as soon as you want to level out the canopy. my first scrog helps organize and stops vertical growth for 7-10 days - which helps keep the plant shorter in a 80" tall tent. It is 5-6" above the rim of my pots. I have irrigation drippers, so i don't have to worry too much about access to the top soil - as long as i can still top-dress seom mosquito bits, it's good enough. If you hand water, that's may require a bit more space for access. I put a 2nd one down a few weeks later that is just for support in case any of them can't hold their own weight late in flower.

Depends a little bit on the goal you have with that scrog net i would say. You could either use a net to give stability to buds and prevent them from flipping over, or use it to keep a low canopy and cover it with foliage as quickly as possible. Looks like you want to keep your canopy low, so i suggest you install the net now and use it to do more light stress training. You can still raise it higher later, it can be a little bit tricky but defnintely possible. Get somebody to help you to make that easier. Or install a second canopy on top of that later. Ive seen people using 3 layers of those nets with insane results. But you should be fine moving that net around later i think! Keep it simple, keep it smart!