"Trying to make the back edge of the blade into a knife is doomed to failure in most cases. Only the teeth are really hardened; the rest of the blade is relatively soft. This is deliberate and good blade design. So any edge you grind will die quickly."
Roger, I already sharpened one, so we'll see I guess. I will say though, the non-teeth portion of the blades is the toughest steel I have ever dealt with and took a long time to sharpen. I once used a single cobalt bit, without resharpening, to drill 200 holes in a pair of disc brakes, which ate a HSS bit in a couple of seconds. I used the same bit on a pruning blade, with oil and pressure, and it only made it through 3 times. If that's not "hard" I can't even imagine how tough the teeth are. At any rate, when camping I usually just carry a small Victorinox and cut nothing tougher than a fish or tent cord.
John, right now I'm in R & D mode, so drilling makes sense because I can do it in my home shop. If I go into production, I will contract with a local machine shop that I have worked with before, and do the cutting by plasma, laser or water jet, depending on what they advise. At that point I probably won't even use round holes for lightening, but rather slots or triangles.
For now, I plan to try a combination of spot annealing (great tip Smoke!) and Roger's suggestion of using a masonry bit. If that doesn't fly, I'll plunk down the $30 for a solid carbide bit. Delmar, I made a small spot welder from a microwave oven transformer and will try that first. I will also try the pencil torch and nail/rod techniques for comparison.
I really appreciate all the responses and information from everyone on this thread.