Or ... just do open source under an alias.
When I looked into something similar I found that while companies will fight tooth and nail to not sign away rights to a specific idea/effort, the law is very much on the employee's side as long as you don't use corporate equipment to do it.
1) Competing with your current company while moonlighting.
2) Leaving your current company and using any knowledge you gained there against them.
3) Leaving your current company and using your skill set at an unrelated company.
Contracts forbidding 1 & 2 are usually defensible both morally and legally. It’s 3 where the metaphorical water gets murky, since overly broad contracts of this type basically deny workers the ability to work and earn money for the duration of the noncompete, if enforced.