I have done this and been there before. Dropbox syncs the deltas in LUKS and veracrypt disks. A change of a bit in plaintext changes the blocks that are involv

I have done this and been there before. Dropbox syncs the deltas in LUKS and veracrypt disks. A change of a bit in plaintext changes the blocks that are involved, and only those blocks are updated. But most other sync tools don’t handle it properly. That was around a decade ago. Today, one would use cryptomator, rclone, gocryptfs rtc.