If I were Larry Scott, I'd invite UT, Rice, UNM, and UCSD as non-FB members.
Trial period until 2031 expiration of LHN. Texas keeps LHN and gets independent PAC scheduling arrangement a la Norte Dame with all games at PAC schools carried on PAC-N.
Rice and UNM are given metrics for facility and on-filed improvements while UCSD is tasked with starting FCS football within 5 years and beginning FBS transition within 10. They initially receive a full PAC-N share (beginning ~2.5M with growth related to added Texas market) with increased share of total PAC contract as metrics are met.
In 2031, they join the PAC as full members with a Border Division of UCSD, AZ, ASU, Utah, Colorado, New Mexico, Texas, and Rice. This retains a SoCal anchor while adding 3 AAU universities and maintaining geographic continuity.