Yes, I know, but when you 1) start with for instance a divisi change with only one division (Add section division, delete section 1) and 2) write music for section 2 (which is the only section) and then 3) create a new divisi change for section 1 + 2 to add music for section 1 then the music entered for section two winds up in section one. I try to simplify my problem:
Creating a divisi change with only one division (number 2) and writing, say, 8 bars of music. Then create a new divisi change with three divisions (1, 2 and 3) on bar four. The music of the one division (number 2) winds up in section one. So, if you want to add section 1 to the already existing music on section 2 you have to move the existing music from section 1 to section 2 before you can continue writing in section 1.
If you have a divisi change with only one division, and add more divisions, the existing one is always the first, or highest one, whatever number you gave it. While you might want it to be the middle one or lowest one.