Originally Posted by
LeisureFirst
I can see good reasons why the airline might want to make it slightly tricky (although as you point out, not impossible) for a passenger to be holding multiple boarding passes with different seat numbers. It's liable to lead to passengers getting in a muddle and at some point pulling out the wrong one.
I agree when it's the airline who does the seat change; but when a passenger goes out of his/her way to change a seat after OLCI, I think it's pretty safe that he or she can recognize his/her improved seat from the original, less desired, one, without the need for a nanny.