Well, lights just came on (starting of the 5th 12-hour daylight photoperiod) and after careful inspection and re-inspection, 5 of the 6 Extremas are confirmed males (including the awesome & bushy Extrema that I was certain would be female based on the plant's morphology, and the cloned top I cut from it):
(*didn't bother with snapping pics of the rest of the boys)
The final, 6th Extrema plant was planted a few days later than the others, so it has a day or two to go before it shows gender. It's the one in the picture located front & center with the wooden clothes pin clipped to the front rim of the pot (it is looking very similar to the other male Extremas, so I have suspicions of it singing contra-baritone like the others instead of alto-soprano like the M1's):
This is what's left of 10 plants:
And all 4 of the M1 plants from dababydroman's s33ds are confirmed female.
So, at least all is not lost.
Now two more months until I toke again while they flower.
Switched to LST temporarily to get them trained horizontal, and to make it easier to move around while I was looking for pre-flowers.
Will re-hang the scrog screen later this week and begin their final training.
Watching the "Lord of the Rings" trilogy on DVD tonight (I have the whoop-dee-doo extended director's cut collector's edition of them all, so I'm good for about 9 hours, plus 6 DVD's of extras if I can't get to sleep after).
Gandalf reminds me of my Algebra teacher in 9th grade: "
YOU! SHALL NOT! PASS!!!"