I noticed there is an Always on Top option in Settings, but I cannot enable it. Do I need to grant any additional permissions? Also, it would be great if the app could read bookmarks from other browsers and support cloud syncing of the JSON file via WebDAV.

Right now Always on Top options can be enabled only when you're not in the "attachment mode". Because when the app is attached to browser window it shows the sidebar only when it becomes active. I'll see if I can find some solution

As for importing from other browsers, this is definitely on my list (at least Chrome and Firefox). I just did Arc first because that's where I wanted to migrate from