Thank you both, I appreciate the advice. But I am not sure if this is exposing samba to the internet that way, but I am limited in my imagination when it comes to network topology 
. The are no DMZs or port forwarding other than that port 80 for the WAN. The only routing this MT2500 is doing is SMB over the local subnet as network filesharing, behind the existing router that has a firewall protection and in some cases behind a CGNAT. If the Tailscale function is turned on with the MT2500 and the subnet routing is advertised in Tailscale, then SMB routing over the internet is protected by Tailscale authentication and Wireguard end to end encryption.
This set up seems to work okay, not the fastest NAS from a router/gateway, but it is not meant to replace a heavy duty NAS.
Any suggestion to test and improve speed and security of this set up is welcome.
USB SSD file share local subnet.
