Switching to 12/12 Faster?

I heard you can leave a plant in total darkness for 24 to 48 hours to make it start its flowering period quicker? can it stress the plant out?

I have also heard you can take a plant ready to crop and put it in total darkness for 24-72 hours without light because this will STRESS out the plant and stress creates more resin... so there def will be stress but not sure if it will be too much to be counterproductive?

You don't want to stress your plant mate, just switch to 12/12 after 14 days of veg and that's the quicker it will get, 80-90 days seed to harvest, if you want it quicker get an auto-flowering strain, 60-70 days seed to harvest.