I would need to see a clear UX/use case for why you might need to read a document in the middle of a tactical crisis situation
It depends how you mean the term “crisis” (it doesn’t mean always danger) and if you want to expand the use of Buoy to other kinds of help. Here are some cases:
1. You manage by distance a team that works far from home, maybe in difficult geography or weather (mountains, difficult countries etc) and they need some docs.
2. you sent to some social groups documents they need to defend their causes (application forms, tutotials and guides etc). There are people that are not comfortable with searching them (especially if they are administrative docs) or they have not time, because they are in a difficult situation.
3. you upload important docs for a critical meeting of your company
4. you sent pre-maid plans of action to a team. In some cases you gain time by sending a plan instead of explaining a lot of information they may forget.
5. Some times people are not involved in a critical situation directly, but are just observers (police violence, etc). They can take photos and, once at home, import them in openoffice, add a description and export in pdf. If Buoy could upload pdfs, the document could be downloaded by the team members and shared to other media. What is the advantage? An observer doesn’t take the risk to be exposed personally by publishing directly to social media. He/she shares the event only to the team and it will be published by someone who has more courage (or who is an activist).
So I think that, at least, pdf upload is strongly recommended. It is not necessary to add a reader; members could download it. If you want to allow more repurposing of Buoy you could add other file types as well.
Have a nice day!