Absolutely do NOT do this! The stress from this will cause your plants to hermie. Wait until you can take some clones, then flower the clones. This will allow you to sex your plants with the least amount of stress, if you can't wait for preflowering.
Even if your plants don't hermie, their internal clocks will be all screwed up and will not grow properly for several weeks. I would stick with buying fem beans and avoid sexing all together.
Ive reveg'd my share of female cuts and never had
1 go hermie on me.
yes, their clock is screwed for a while...
and they all grow out of it...I can't see a prob with that?
its an accepted common practice from what Ive seen here.
on the other hand if a strain can't take all the *stress* and does hermie.....
dump it, its a shit from the git go