Just found this thread, as I was searching for a way to sync my bookmarks across different browsers on Windows, Mac, and iPhone. I am currently using XBrowserSync and Eversync (Everhelper). Both work great and allow any changes that anyone in my family makes to bookmarks in Chrome, Firefox, or Edge -- at work or home -- to propagate to all of our devices, Windows and Mac. Unfortunately, to use this extension (or any other), one must disable any native browser bookmark sync (Chrome, Firefox, etc.), as failure to do so will result in a mess as multiple systems try to sync data. iPhone browsers do not support extensions, so Firefox on my iPhone cannot get any of the bookmarks saved on Windows or Mac.
I was hoping Orion would be my solution, even though there is no Windows version yet. Unfortunately, neither of the two extensions works on Orion, either on mobile or desktop.
To answer Vlad's question (reiterated frequently, as a clarification of complexity and cost of development): I am an Orion Lifetime subscriber and Kagi subscriber. I would happily pay more for a working bookmark syncing feature to enable headache-free access to all of my bookmarks via native bookmark interfaces in Firefox, Chrome, and Orion.
Thank you for all the hard work and effort you put into continuing it.