@Greentimedevelo
Hi, thanks for the feedback.
There hasn't been a plan to support a VPN server on Archer MR505.
As most SIM carriers use CGNAT service, the 4G router hardly receives a public IP address. If the VPN server is behind a double NAT, you might need to request external access from the SIM ISP side as well as configure port forwarding on the Archer router.
Would there be any specific reason that you want to set a VPN server on Archer MR505?
Best regards.