My everyday shooter is a sinew backed osage flatbow and it has linear cracks from the fadeouts almost to the tips. None run out the limb edge and I bet some go all the way through to the sinew. For the first few years it would give out with the most frightening clicks, clacks, ticks, tocks, pings, sproings, etc, but she ain't blown yet. I tried filling the cracks with superglue, but ran out of money and was ruining some really good squirrel habitat.
I would love to say I knew what I was doing, but I didn't even make this bow, my bow mentor did. In polite company she is known as "The crack addict".