Could expansion make a difference? Not if you're talking the current group of candidates. BYU is attractive because of its national appeal, but it has a network of its own, too, not to mention travel and scheduling concerns.
The rest -- Cincinnati, UConn, Houston, one of the Florida schools -- all have some appeal. But none moves the needle. This may hurt some feelings, but the last thing Texas wants is a reconstituted Southwest Conference. Besides, if you give, say, Houston a seat at the table, you make it even more viable with recruits. And Tom Herman is doing enough damage as it is.
If you add a school that couldn't even bring TV markets you already own, or doesn't promise others, what's the point? No use dividing the pie any further.
Any expansion talk should begin with Florida State and Clemson. They'd give the Big 12 a national footprint, balance the West Virginia side of the league and, most importantly, provide quality football competition and traditional fan bases.
One little problem: the grant of rights both schools signed with the ACC, forfeiting any TV revenue should they try to bolt. Runs through 2027.
Boren is well aware of such problems and told the World he's not sure what would happen if schools challenged a GOR in court.