I was departing from KORD on the expert server, and the ATC was a member of IFATC (which I think it one of the professional ones).
He assigned me 27L (~8000ft length), but I was very heavy and needed 28R (~13000ft length) which ATIS allowed. I re-requested taxi to 28R, he warned me not to send duplicated messages. I taxied on my own to 28R, he threated to ghost me if I didn’t follow his instruction.
Same thing happened before at KSFO, I was heavy and needed 28L/R, the ATC assigned me 1L.
What should I do, takeoff from a short runway and crash?