I had the same thought and contacted F2 directly. I did get a response and they have considered this but are unable to do it.
The only reason they cant is that in Monaco qualifying, they split the cars into 2 sessions. They run even numbers in 1 and odd numbers in the other. The system is quite inflexible so wouldn’t allow any other way of doing it.
I suggested they get around it by listing the numbers in order and then finding the 12th number and do 1 session for that number and below, and a 2nd session for car numbers higher than that. It doesn’t allow them to do that annoyingly.
I agree it would’ve been nice to see and have drivers keep the same number all the way through.