I sync all the files in ~/Documents via Nextcloud with three Macs running macOS 10.13, 10.15 and 11.0, and additionally with a PC running Windows 10 by Nextcloud Desktop Client. At the moment at the Mac which is running 10.15 I have installed DT3 and having a database which has being indexed all files in ~/Documents. Now, I want to sync and keep being synced this database between both the Mac sunning macOS 10.15 and 11. And possibly by future I want to have access to this database via DTGO via iPhone.
What is the most reliable way to keep this database being synced: iCloud legacy, iCloud CloudKit or – my favourite – Nextcloud?