Need pruning advice on large plants prior to flipping from veg to flower

Hydro in totes, 1000w HPS.

Long story short. I have 6 plants that were vegged out for months. I didn't intend to veg that long but this is grow #1 and I had some challenges before I got everything dialed in.

They are bushy monsters. About a month ago (at the advice of a fellow RIU member) I bent them over sideways and laid them down almost horizontal. The goal was to get the side branches to all grow up like a long bush.

Problem: They are packed in tight and definitely going to be candidates for mold issues and popcorn buds if I don't thin them out?

Questions:
1. Should I top these to stop them from growing taller? I know that originally was going to be my main cola but now that they are horizontal and growing like crazy (with the flowering stretch still on the way).
2. Can anyone suggest a solid idea for getting these ready to switch to flower? Maybe trim all branches that are on the bottom side? Or any branch not reaching for the light? Something that a beginner can understand and not screw up too bad.

I attached some pictures but its hard to really see what is going on, other than they are really bushy and overgrown! I drew a little diagram to help out too.

You have enough headroom for them to get 2X-3X their current height? Otherwise additional supercropping may be your best option.

Here is a guide

Tough call, how heigh are they ?

As long as the leaves arent causing problems, I would leave them on.
After the stretch in the flower phase you can prune and trim some if need be to increase light penetration and airflow within the canopy.

If there is insignificant growth at the bottom where light eventually cant penetrate, remove it.
It will yellow and rot otherwise most likely.
You can still access it now relatively easy, during the flower youll want to avoid touching the bud sites as much as possible.

Thats quite a field that sprung from those plants

Imo it could do with the 12/12 flip already.

Yeah I agree , you have more than enough head room I would lollipop the shit out of them..
Like said the bottom third will not recieve much light and prolly die off anyway.
If you top them the will grow more side ways and you may not get enough air flow through there
, I would flip now. Just My 2 Pennys..
Good Luck..