Could this be the reason I find OF sync to be slow relative to my native apps and documents?
iCloud consists of two main services: iCloud Drive to sync files stored locally and in its cloud storage, and data syncing for apps that share databases in iCloud and use CloudKit to manage their shared data. Those who are paying Apple princely sums each month to store files in terabytes of iCloud Drive will be relieved to know that this throttling doesn’t appear to involve iCloud Drive at all, although that does of course have a storage quota enforced. Throttling only affects shared data that relies on CloudKit.
Mine are around 3MB, and I have never “archived” older items in OF (the dialog that keeps popping up from time to time). Granted, I am not a heavy OF user… I use… Reminders!. But if you created your OF database from scratch when OF4 was released, that’s quite a lot imho. You seem to be using either a lot of attachments, or very huge ones, or have a very old database that has never been cleared.
I am not sure about the details of Omni Sync, but I would assume that heavy attachments will take its sweet time to sync to other devices, but once the attachments are propagated the sync should be fast.
Try this one: sync everything on all your devices, until the sync button does nothing. Then add a dummy task without adding any attachments. Is the sync still slow? How long does it take? Do you experience slow sync across all your devices? (I cannot seem to find your original post, sorry)
Other options to explore beyond the “Archive old items” are the “Rebuild” and “Compact Database” options in OF File Menu. I know for sure I don’t need to remind you to have your backups ready before attempting those