I really think the best current place for BYU (absent an all-sports invite from the P12) is a FB-only invite to the B12, coupled with a scheduling agreement for BB. But BB and all other non-FB sports would remain in the WCC.
And I'm not "April Foolin'" about this.
But, unfortunately, the reality is that it's likely that BYU will stay in its current situation (indy for FB & WCC for everything else) for the foreseeable future.