the only evidence i have is anecdotal, but here it is anyway...
ive bottled a batch once that apparently still had some fermentables in it (not sure how much), ontop of the recomended amount of priming sugar i added. but i used a combo of grolsch and regular 12oz bottles, and had almost all of the 12oz's grenade while the grolsch bottles were fine. they were very
overcarbonated when they were opened, but none of them exploded, so they can obviously withstand quite a bit more.
actually, ive never had, or heard of, a grolsh bottle exploding. if any of yours do, certainly let me know