I made my own tunnel system with a $5/mo vps that runs kernel wireguard and accepts my nas' public key. Once connected it DNATs 80/443 traffic down the tunnel to the nas, where its routed to caddy.
The vps runs a custom image that is 2.54 Megabytes. It has a custom kernel with almost everything but networking and wireguard disabled, a fixed-size fs with pre-allocated blocks and inodes to hold the vps wireguard key, and a single pid 1 binary that calls the kernel directly to set up the routing rules, generate a new wireguard key on first boot and save it to the fs, print out the wireguard public key to the console, and loops reap. Updating involves building and uploading a new image, assigning the vps to use it, reboot, wait for the public key in the console then set it on the nas so they can talk.
The vps runs a custom image that is 2.54 Megabytes. It has a custom kernel with almost everything but networking and wireguard disabled, a fixed-size fs with pre-allocated blocks and inodes to hold the vps wireguard key, and a single pid 1 binary that calls the kernel directly to set up the routing rules, generate a new wireguard key on first boot and save it to the fs, print out the wireguard public key to the console, and loops reap. Updating involves building and uploading a new image, assigning the vps to use it, reboot, wait for the public key in the console then set it on the nas so they can talk.