Genserver/otp layer in nodejs/typescript?

Totally understandable.

Just recently someone wanted to use a somewhat similar setup (though Rust instead of TS) here on URLO, i.e. use SSH to run a command on a remote server. I think you could achieve this with the ssh2 npm module. From your controller (your Node app), open an ssh connection to each cluster node and run the rust server, using the status code to restart if the rust process panics.