If Coffee Stain were to incorporate telnet access to the game console, it would expand on many aspects of gameplay such as multiplayer session control, and the construction of simple external tools. One ready example I can think of to suggest what adding this feature would be capable of, is Fallout 4’s Pip-Boy app. Coffee Stain wouldn’t even need to develop apps or utilities such as Pip-Boy, the community could, and would, use such an access point to build interesting and dynamic things for the game.
Off the top of my head, one utility I can think of that I’d develop myself, would be a non-intrusive appliance load monitor. Given access to the data displayed by the in-game power consumption graph, I could write a small program which would log into, or stay connected to, the telnet console to poll and monitor this data, derive a list of individual consumers based on the fluctuating data, or input those parameters manually, and display a semi real-time graph with indicators of suspected off-line producers through an external program.
Another more tangible, and probably more popular utility, would be one which displays the player(s) current position, inventory, global inventory, time of day, ect. If executable access were granted through this telnet, a utility could be created which would allow novel features such as automatically switching held items based on conditions, or moving specific inventory when a player opens a container.
Ultimately, implementing a telnet port into the game console, would be reasonable simplistic, would make basic modding more accessible to those with only rudimentary programing skills, and would give all players the ability to customize their experience without having to mod the base game.