If you're not doing any hard chopping, prying or twisting with the edge, then there're no worries at 15°/side, or even lower. Consider that, by their own sharpening policy, Buck Knives aims for 13°-16°/side (26°-32° inclusive) for their knives in 420HC. Cutting geometry is great in this ballpark, and Buck has arrived at that target via testing of edge durability (thru CATRA), which shows the edge cuts better for longer in this range.
I don't even consider anything higher than 15°/side anymore, for any knife I use. I don't even microbevel any higher than that, on the infrequent occasions I actually use microbevels at all. Most of my edges are generally closer to 25° inclusive (12.5°/side), and some are likely lower than that. The key is in using the knife as it should be used (as a cutting tool), and not as a prying tool or screwdriver.