Cheese, congratulations on your situation. I've read the entire thread and understand your views on your work situation.
I would only add the following for your consideration. As a chief executive/equivalent, I have led the purchasing of several companies and been on-point to customize earn-out deals of the nature you describe, as well as negotiate and close on many senior hires and legal partners. All of those deals had contracts and rigid legal structures behind them, carefully negotiated with the right intent in mind to satisfy (slightly dissatisfy?
) all parties at the time.
However, many of those deals ended up being scrutinized as circumstances changed or needs of one or more of the parties changed. I can think of a number of instances where it was easy, convenient and very appropriate to change the terms of reference.
I would just seriously invite you to think about changing yours. You are NOT a servant to a deal if you don't want to be and your partner(s) agree to talk about it, you don't HAVE TO do anything you can negotiate out of, and five years is a hell of a long time to be "locked up" in something in your 50's when you are already financially independent.