Should I harvest any of these plants or wait

Let them go. Buy a jewelers loupe on Amazon or use a magnifying glass and look at the Trichomes on the buds, not leafs but buds. They go Clear-cloudy-Amber once 35"% are amber chop it down

They look amazing, and I'd say you're not too far off with the 2 weeks left, I'd personally about 3 weeks if you're going to flush. Loving the Frost they produced.

@mr_weeds_autos @Sweet_seeds @Bluntzilla @Roberts anyone any opinions I did notice when I've run the girls at 769ppm I done minor damage but feed is reduced to 450ppm and will reduce futher over the next 10 days then stop altogether ... plants are still drinking 1.5 liter or more daily, air exchange was ramped up 180m2 per hour and lights are able to run at 1060w at 21oC heater is on constant and got Ona PRO block 170g ... my good any concern from the smell of the plants is gone these little blocks are amazing... I couldn't smell the girls at all within the tent and plan on ordering a few more for drying as these are powerful little blocks ... natural essintal oils safe for plants BRISTISH Irish Russian French Italian these little blocks do super at hiding any smell related to the product growing... says works for 4 weeks I need it to only work for 2 weeks and then I'll replace it ...