Odd idea popped into my head at work last night. Figured I'd see if someone has already done it... could someone machine a rear island into picitinny rail? It's odd, but hear me out. A micro red dot like the aimpoint t1 could be picked up super fast and it'd be much lighter than the large red dots that utilizes scope rings, and it'd be easier on aging eyes that iron sights. Has this been done? If not, is there a mechanical reason or just a purely aesthetic one?