I had shared this a while back, and this is still that we all know just based on experience. No more details from Pia yet.
A friend in Japan let me know how these things work in general. Group A is 1-100, Group B is 101-200, and so on. If you are ref #220, you are directed to Grp B by a staff member. Within this line it is first come, first serve, so you could be waiting ahead of #200. Once the doors open, the lines enter in order
of the 100's, 200's, etc. This is how it is organized within each of the blocks.
Taken this is based on his experience, so things could be different for the U2 shows.
So, even though I'm 1052, I could be the first person in line for the 1000-1100 group. Assuming that the ref numbers begin at number 1, I could have up to 1000 people going into the A block ahead of me.
As for cutting, doctoring, etc. I really don't think that's the Japanese way of doing things. They are very accustomed to the organization and structure of GA lines, and respect the staff assigned to manage the lines. I'm sure that there are a few that find their way around things, but I know I'm not interested in breaking the rules.