Offering this feature would not only make a lot of your current users happy, but it would also be a huge incentive to prospective users and would attract a lot of positive attention. If you'd like evidence to support this notion, check out the 'selfhosted' subreddit and similar subs. Many people, me included, appreciate the ability to limit where our data is stored. Consider giving the user the ability to choose exactly where our password database is saved, and how/when it is synced. Allow us to limit syncing across local networks, and selfhost our password data, with the ability to opt out completely of having any of our stuff synced to your servers. Yes, I know it's zero knowledge, and AES encrypted, but still, there are advantages to what I am positing that speak for themselves.
