Tailscale vs. Local access

As I think more about using Tailscale, if I have two NAS devices in two separate locations (~100 miles apart), can they be connected via Tailscale (as a persistent connection) and still be accessed locally? How would Tailscale work if I were in a remote location and wanted to VPN to NAS 1 and someone else (an authorized user - a separate question is would I be able to give them access under their own account or would I need to give them my userid/password for the free version) wanted to VPN to NAS 2? Is the concept of Tailscale’s mesh VPN that all the devices associated with your “mesh” are given unique IPs and then once you login to Tailscale you can route to whichever other device is on the mesh by using their specific IP? (not sure if that makes sense but it did in my head)

How would it also work if the NAS devices are on the mesh VPN and someone on the local network wanted to access the NAS (via smb or Synology Drive)?