Cheers! OK, If you start thinning a lot, you will loose a lot of yield and slow down the plants in the most important stage of development. If you let them get leggy, bud development beneath the tops will suck and you will think that scrogging sucks ha.
If the pic was taken at one week 12/12, your stretch should be about over in another week to 10 days, and yes, it will be busy, but keep putting them under, you will be fine. Once it gets to difficult (more break in the process then not) you can also tie them down, tie them out of the way, remove parts of fan leafs that cover major but sites etc. Take a look from underneath the screen and you will see plenty of room there. You can also still better position some of the branches, just pull one back that is in a crowded place and redirect it to a less occupied area. If you have the room, raise the screen a bit, that buys you a lot of room, great advise from the guy above
just make sure to maintain light distance, otherwise they will stretch more to get close to the light again.
Now, it is crucial that you can maintain humidity (below 50% once buds start to form) during flowering, especially within a dense canopy. Several fans gently blowing into the canopy would be great.
Keep posting updated pics, like daily, so we can see how fast they are stretching, and help you out along the way.
BTW, they look great, if you do this right you will be a happy man