They contacted me and said the bolt shouldnt have snapped, and that its a strong part. They will be sending me TWO replacement bolts. Cool of them, but I dont trust them to hold any better. I realize that its just too long of a span to support with that bolt. In my opinion, the fix is to use a proper 8x54 shock mount hardware, that way the strong tube spans the whole 54mm width. I could drill (or ream) the tube out from 8mm to 10mm and it would still be relatively strong, and I would be able to use the replacement bolt. But honestly, I think the strongest configuration is what Ive already got now. I just need to dress it up with a clean looking button head sex bolt. Wow, that sounds dirty.
Another option I thought of, other than fabricating those adapters out of chainring bolts, is to simply replace the pressed in bearings with ones with an 8mm inner race. Then you could use the 8mm bolt directly without any sort of adapter. That would be clean. I'm currently using 5/16 washers, and they are a perfect tight fit, acting as a dust shield. Maybe Ill pick some up in black oxide, or maybe ill just paint them.
All in all, I think I'll consider what Ive done to be an upgrade / mod and leave it in place, rather than risk what could be a catastrophic failure. If anyone wants to play it safe, I would certainly suggest going with the trunnion shock given the choice. But if you already have a standard shock you want to use, dont shy away from the frame just because of this issue. Modding it to use 8x54 hardware is trivially easy to do.