While agree with you an awl punched stitching hole is more workmanlike, and possibly closes up better.
I switched to drilling & a countersunk thread line years ago to protect the thread from wear..
http://www.tandyleatherfactory.com/en-usd/home/8069-00.aspx
After I had a diamond-awl break in half, go through my left thumbnail near the cuticle, and pin my thumb to the maple cutting board I was using for a work surface at the time.
After I got my left thumb un-nailed from the cutting board with a pair of pliers I had to carry the cutting board too go find??
I went and changed my peedy-pants and put on a bandage.
And right after I grew a new thumbnail 6 months later, and could do leather work again?
I started drilling holes with a 1/16" drill bit in a drill press.
If anyone has noticed my stitching holes not closing up in the last 25 years or so?
They never mentioned it.
What I have found is a drilled (basically burned hole) from the clogged tiny bit in wet leather is less likely to rip out a seam on thin leather.
As the edges of the holes are further apart then they would be if you do a 'tear it here' line of 45 or 90 degree diamond-shaped piercings with a diamond-shaped awl.
I
greatly admire your most excellent work you have been posting lately.
And if a diamond-awl is the way you do it, then that's the way to do it for you!!
It's just not the way I do it myself anymore.
rc