First of all, we don't know what position coach they are looking for, but if a DL coach why not Travis?
He has been coaching (albeit private) for the last few years, seems to love teaching technique and have a passion for it. Maybe he does for the D-Line what Harvey has done with the RBs.
I know there is a lot of options out there and maybe the right person is like Mateos a GA at large program, but I think if they are looking for DL coach, Travis could be a candidate.
Article:
https://kslsports.com/436934/byu-football-defensive-line-travis-tuiloma/?