Before freelancing, I had to turn down many jobs where the company wanted to "approve" my off-hours work. Never a CTO role though. The companies that I did en

Before freelancing, I had to turn down many jobs where the company wanted to "approve" my off-hours work. Never a CTO role though. The companies that I did end up working for would add stipulations in the contract - they still wanted any extra work I did that was in the same field but agreed to filter by their verticals. IANAL and any court action is a loss IMO.