Backup 3-2-1
3 copies; 2 local on different media; 1 offsite
I use Mac TimeMachine for incremental backups to a local drive
and cloud service Arq Premium for incremental backups to a cloud location
> I need to access these files from multiple MacOS and Windows computers.
You can leave the folders/files on the NAS at their current location
and use the Indexing option for access through Devonthink