Can fell your pain, know it to well. Think that is the biggest drawback to doing larger seed populations indoors, running out of space, and everything else waiting to be able to kill the males.
The phylos testing, you can sex them at cotyledons. Supposedly its legal to no matter where you are located, since you are only shipping a smear of genetic information, not a plant.
Have seen friends, rushing to put seed starts out in Spring, stick the plants in a completely dark closet for a few days, to induce sexing quicker. Myself I never tried it, so I cant say with certainty, but I do feel like it has some merit.
Lastly, recently I had someone mention that Kelp may prolong sexing, as in if your waiting to sex, don't go nuts on the kelp. Myself I love kelp, so hard to stay away.
I feel like a lot of it is genetics, one cross will sex in 3 weeks, another takes 6.
Gl, and enjoy chopping the males and regaining some space!