we have award 2 tickets biz class, iad-lys-fra-iad. the fra-iad is on lh. i do not have seat assignments. when i fly award lh or os, i can reserve seats. is there any way to get advanced reserve seats with this ua award? even to the point of calling lh or ua? i did a psuedo booking of the flight, quite surprisingly, biz class is slightly over half booked already.