All of this ^^, OP bro needs to chill and let the plants finish on their time without any more " experimenting" lol
Flush if you want, taper nutes if you want , those are choices you make as the grower, the plants will finish when they finish, noway of speeding that up but you can hurt your crop by being impatient. I learned this the hard newbie way.
I chopped my first plant early after being impatient , it cost me in yield and quality, my next 3 all came down when they were truly done, the waiting paid off big time. The weed from those 3 is so much better than #1.
You have done well with the plants, they look good under normal lighting, no doubt you will harvest some nice bud when the time comes.
Best of luck the rest of the way.
Relax bro, you got this lol