Since playback is an important part of composition process, on first glance wouldn’t it seem that you want solo players for each of the parts instead of section players? Or am I misunderstanding something?
If I want to show two Horn staves, each one with two solo divisi players, I can set them up as Divisi 1 = Horns 1.3 and Divisi 2 = Horns 2.4. Each individual player has it’s own note in it’s staff, and each plays back as one horn. If I were to use section players, wouldn’t I end up with four players each playing back as a horn section, thus resulting in a four-section sound?