One thing that I haven't understood is syncing. How do you sync passwords between different desktops/mobile devices?
Send the KeePassXC .kdbx password database to your cell phone, download it to your phone, then upload it to Strongbox (or other). I find the easiest way to send it to my cell phone is by using Signal's "Notes to Self." All my devices that have Signal and have KeePassXC then have access to the updated database.