Okay another update.
Just called the fake Plat line again. Asked, very nicely, to get assigned to 1A. Was told that I couldn't because IT WAS ALREADY ASSIGNED! So then I mentioned that I had been trying to get that assignment for 3 days and was told that it could not be assigned except day of dep at the airport, but that now, all of a sudden, it has, in fact been assigned. Answer..."good point, you got me.". I then asked why, if that is the policy, I was able to be assigned 1A on my other RJ leg the next day. Answer, "again, you got me". So the agent put a note in the record that I want 1A.
What managerial incompetence. Man, they must have laid off all the knowledgeable people.