it should come back,colder water ,lower level and some sort of root treatment.what you had was lack of air.
like over watering a dirt plant,it stops air from getting to the roots. good luck.
Sudden wilt from the rockwool being in the water all the time. Got to keep the RW up out the water and treat it like dirt meaning you have to let it dry from time to time.
different composition of the 3 part nutes are causing it to burn? happened to me switching to chem-gro so its possible imo. I would lower ppms even more 550 if you were to try to fix it and go back to veg.
You could try to foliar feed a really light ppm 150 once a day.
My understanding of it is to just switch the lights back. My main point is to heal the plant so its healthy when you go into flower again, instead of dealing with an issue that is stressing the plant.
I think you should start another set and play with this if you want but keep the expectations low.