Glad to hear you’re up and synced via Bonjour!
Regarding a remote sync, we don’t advocate one service over another. iCloud seems to behave better in some instances (or just on some days) and for others, not so much so. That being said, you are correct that iCloud / CloudKit is a sore topic for many developers (and users) so if I were to be asked over a coffee or an adult beverage, I’d opt for Dropbox - again, with no affinity for the service.
But as noted here, any remote sync option comes with it’s inherent weaknesses…
One side note: Many people feel Dropbox is too intrusive on your system. (I will reserve my comments for the second coffee or adult beverage - LOL). That being said, Dropbox’s application is not required to sync DEVONthink with it. So if you’re only going to use it for non-syncing use, I wouldn’t even install their application.