Well I'm in on this. BLR-FRA-EWR-CUN. First two legs on LH, final on UA. Fare class A, A, B. First flight LH flight #, FRA-EWR with a UA flight #. Pulling up the reservation on LH and I can select a seat in F for first leg and Prem Y on second. Crediting to A3, so hoping it is 300%...