I'm not really convinced by the proposition. It seems messy and complex. Imaginary_username asked the good questions here.
Don't forget that Bitcoin Cash is supposed to be p2p cash.
Increasing the utility of a thing increases its value and usecase as cash. At this point i don’t think a coin can pursue the p2p cash usecase on its own.
Not saying we shouldn't have miner-validated tokens, but the proposal seems kind of messy and could affect protocol simplicity. There might be a better way to do this.