A plan gains a pulse the moment somebody acts on it.

A plan is a description until someone acts on it, and descriptions can be revised forever without ever encountering reality. The first action is what converts it into something living, with actual constraints and actual feedback. Everything before that is speculation dressed as preparation.

Take the plan you have been refining and do the smallest real thing in it today. Send the message, buy the material, book the time. The plan will change on contact, which is the point.