1. YC is not gospel, and (by definition) none of their companies are bootstrapped. That means their experience and advice aren't necessarily targeted at people like you.
2. Clerky isn't a substitute for a real lawyer. You and your co-founders might have needs/preferences that aren't represented by a "fill-in-the-blank" document.
3. Clerky is YC-backed, so the recommendation to use Clerky should be taken with a grain of salt.
I can't stress this enough: talk to an experienced, real-life startup lawyer. There is no substitute. I know that seems old-fashioned or inefficient to our crowd, but I've learned the hard way on several occasions that you shouldn't do your own legal work. The cost of getting a professional to do it is so low that it's a no-brainer.
Related to the law you mentioned: it doesn't matter what the vesting schedule is. 20% is 20%. Furthermore, the law is similar to the internship law. Someone has to feel wronged and then report you to the govt or sue you in order for it to be a problem.
Basically the law is trying to protect early employees from being exploited. It's not really targeting founders. Of course, you should verify those statements with a lawyer, as I might be wrong.