Yup, they lack any standard markings and they have a corrosion resistant zinc finish (so they look like SAE grade 8 bolts), but if you look up generic bolt torque specs for 8.8's of that size/thread, they match up exactly with the factory torque specs. 10.9 torque specs are a good percentage higher.
Under "basic info" in the first post, you'll be happy to find that Class 10.9 bolts will be included with the main reinforcement at least at 4 bolt locations. They're kind of expensive for bolts, but I've factored those into the price
2 x 8mm/1.25 bolts that clamp the rear bearings down and 2 x 10mm/1.25 bolts at the front input shaft and pinion bearings. If I can fit it into the base price, I'll try to get some 8mm bolts along the top and bottom in as well, those are in lengths that are much less expensive... at least at the important positions. High grade metric hardware is surprisingly hard to find in the lengths that I'll need here in the states. Pricey too, I can see why Subaru went to a lower grade.
Once I get the design and tooling for the main reinforcement hammered out, I'll likely look into the details of putting together an entire class 10.9 5mt bolt set. Shouldn't be too terribly expensive, and it would be sort of silly to use the crap factory hardware on a rebuild or gear set install if I can make the 10.9 stuff available for a reasonable price.
Glad to hear your interest is growing. We'll see how the diff brace brace holds up in real world testing, and I'm anxious to get a pre-production main reinforcement made to send off to Dylan @ DS1 so I can get his expert analysis.