I get wanting to keep him at BYU. He's an excellent coach. I'd just prefer to keep him running a great defense. Pay him whatever it takes to keep him but don't burden him with the extra administrative crap the HC has to do.
If you think the offense needs a similar upgrade at OC, then do that. KS is fine as the HC dealing with the media, boosters, public, admin, etc. It's more important IMO to have outstanding coordinators than HC.