So the elevator pitch for this is "if wait-for [1] isn't sufficient and you want a go lang binary to evaluate the behavior or response of the request"?

https://github.com/vishnubob/wait-for-it

I however suspect that I wouldn't use it, if I was still working in devops. The niche where a simple wait for the port is insufficient is _extremely_ rare in practice... Because almost everything that needs such either already has the concept of a readiness check to make it available (k8s, LBs, etc) or will retry automatically given the port being open (DB connections etc)