Have you thought about how countersunk hardware would work in those locations instead of hex head fasteners?
Yes, I did think about that. The problem I see is the plate is only 3/16" thick. Once you countersunk a hole far enough to get a tapered, flat-headed bolt into it flush, you're pretty far into it. And then you are only flush. You would have to use an allen socket fastener, and I think it would be easy to grind up the head enough to not be able to get a wrench into it. Now you could get away with shorter bolt guards, but you still have allen head fasteners. My experience has been that unless they are the really big sizes, allens are not great for higher torque, repeated use applications as they strip the heads out easily.
Now I did consider a different way of having them all fully countersunk but still with reliable hex head bolts. It would have to be done with all saddle brackets like the one I made for the rear guard and not use any of the stock holes. The issue with this is it would be more parts and much more complicated to build, and would likely make a substantial price difference.
So short answer, yes, they could be countersunk using the stock mount points, but it would not provide the long term durability/reliability/ease-of-use I would want for putting my name on it.
I could do them fully countersunk with reliable hardware, but it would be expensive. Certainly the ultimate, but very expensive.