I'm missing something. The idea is to reduce injuries on kickoffs, but the solution is to basically have the team punt instead? Would punts result in fewer injuries? In my mind punts and kickoffs are not that different as far as the action.
If punt returns indeed have fewer injuries, then just have the scoring team punt from their own 40. I'm tired of seeing kickoffs sail through the end zone anyway. But not having an onside kick option I think is a problem.
The scoring team getting the ball on their 30 4th-and-15 idea is a non-starter with me. Perhaps that's the workaround to the onside kick issue, but it's not a good one.