If you wanted to go overboard, don’t even make the server accessible publicly. Distribute keys to a Wireguard network that is accessible publicly. Mandate your players obtain keys from you to play.

You can restrict the size of the ramdisk so you do not end up killing processes. A large amount of ram is not mandatory.

tmpfs is the filesystem you are looking for. You can mount it like any other filesystem in /etc/fstab.

tmpfs /path/to/transcode/dir tmpfs defaults 0 0

I transcode to ramdisk.