Link to one command: https://pastebin.com/nFmYk4Bm
You will have to use https://mrgarretto.com/cmdcombinerpro/ Also one commands are currently broken in the snapshots so you will have to spawn the contraption in 1.11 and then update.
You can set $x $y $z to determine the size of the update box.
I made the contraption so it can also loop itself. Just use the contraption on itself by placing down the armorstand close to it. If al command blocks are changed the next conversions should happen in 1 tick!
Only for 17w17a and up.