AIUI, under the proposed system, Agilebits would have to do permissions prompting every time the user created a vault in Dropbox, which adds friction to the pro

AIUI, under the proposed system, Agilebits would have to do permissions prompting every time the user created a vault in Dropbox, which adds friction to the process (makes it less available). They would also need to provide a reasonable migration path for existing users, which, for those who encountered problems, would result in them not having access to existing vaults or the vaults not updating correctly (loss of availability).