I grew Jillybean some time ago. First two males, then two females.
I followed the 70-degree germination trick a couple of months ago. One God's Gift, one Pennywise. Both male.
Germed again 7 weeks ago -- just flipped and will know in a week or so. I tried to sex three-week-old cuttings, but they still hadn't shown sex when I flpped. Two Pennywise and one God's Gift.
I think they are. I think they're more stable overall. But I dont grow them anymore. For the reason you illustrate here. I veg for a fairly long time and have raised some right fine looking plants only to have them turn male on the flip. I once had 8 out of 10 turn male on my after a long veg period.
Now, its nothing but fem seeds for me. Its what works best for my particular situation. The crapshoot thing just isnt convenient for me.