I definitely need sync with multiple devices (e.g. laptop & computer).  It is important for me to have my history, annotations and bookmarks WITH TAGS synchronized...

Ideally I can use different server providers like dropbox, drive, mega.nz or my own private server endpoint...

I have been using the extension for a few hours and find myself constantly adding sites to the blacklist. Have you thought about implementing a whitelist instead? Let the user to opt-in what sites they want indexing. I have seen others also commented on security concerns because of financial or health institution sites are captured by default. I would think a whitelist would be much easier to implement than trying to figure out what needs to be on the default blacklist?