If it clears, send it!
But seriously, wouldn't it stand to reason that a tighter clearance would be LESS likely to have any rocks/ pebbles get stuck in there? The rim isnt going to get smaller, and if it does you hot bigger problems than that clearance.
I too am running wj brakes and 15s. 15x10 3.75 bs (I think) 35.12.5 tires. My clearance is minute. But it spins freely so calling it good. I have few miles on it wirh the akebonos, but the teeves calipers I just replaced were pretty much the same in that regard.
Maybe I'm not calculating something that could raise an issue.. but even a 16" rim, you think an extra ½" would change much? Only thing I could see is if the rims/ tires were balanced and needed weight right where it could be a problem. My rims are balanced and all clears, sounds like yours clear too.. just be cautious who you have balance em, and up front about the clearance tolerance in that area should they need to add weights