For some reason, I can't get Abiotic Factor to actually open up ports 7777 and 27015. I have them forwarded in pfsense using a copy of the rules I use for my other containers, but it still shows inaccessible and doesn't show up in the game's server list. It is, however, available via LAN?.
Edit: I fixed my own issue. Turns out there wasn't one. I just remembered you can't access internal services using an external address if you are also on an internal address. Turning on my VPN to change networks made the server show up in the public server browser.