There seems to be a little confusion regarding these blanks. There are definitely two different versions, so beware.
One version is reported to be dead soft, most likely requiring more than just the axis pin holes and ejector to be hardened. It also apparently has a sanded finish making refinishing a little more difficult. The difference is easy to spot, the Sportsman guide (and some other vendors) does not have the chicken feet.
The ones that Copes and AK builder are selling are (from what I can tell by finishing a couple) exactly the same metal as the flats that they have been selling. Making hardening and refinishing the same as we have been doing all along with the flats.
Here is a comparison of a bent blank from Copes and a flat from akbuilder that I have bent. They appear to be the same.
I took a center punch and gave them both the same whack in a spot that will be covered by the PG. The results were identical.
Top pic is from SG website