As an exercise, and because I am hoping to get up a game amongst the beta testers, I am setting up a con game that I designed some years ago in Roll20. In this game, each character consists of four pages: three Word documents and a hand-filled form. I'm going to have to scan the forms, I guess. At the con I photocopies two of those pages onto each side of an A4 leaf, so that each player had one side of two A5 pages to read before play and one side of two A5 pages to work from during play. That that's not practical here.
Now, of those four pages, one is a character description with a picture, a phrase describing professional role, a phrase describing persona, age, homeworld, biography, family, hobbies, biomods, and relationships to other characters. That stuff has all gone very well into that pop-up page thingie that you get when you double-click on the characters in the character menu. No worries there. Second page is a briefing on the setting and the situation. Four characters get one version, and the fifth gets a slightly different one. Third page is a character sheet, which I'm going to have to scan, I guess. Handout is the obvious way to distribute those, and each player gets a different one. Fourth page is an equipment list, different for each character.
What I would like to do is to set up the characters so that each one comes with the biographico-thingie, the appropriate briefing, the appropriate character sheet, and the appropriate equipment list. But I can't, because I can't attach handouts to characters, only to players, and I don't have any players in the campaign to attach things to at the time I am preparing the campaign.