Hi,
You may say, "I'm ," when you are ready to go. Would you use this construction "be good to" with "good" meaning ready with verbs other than "go"?
I can't think of an example of such a use. Good to go is a fixed expression, which I believe originated with the NASA flight control people, who used it to mean the rocket was ready to launch.
Do you know the expression hot to trot, which is somewhat similar?
Best wishes, Clive