I apologize if the following comes off as harsh, but it comes from experience, not malice. Where can I find people like you who will work for free on the promise of future money dependent on a roll of the die which is funding? Please tell me. I'll take one CTO, 2 senior devs, and 4 junior devs. Here's the deal. I don't know your situation, but you are basically saying that your time is worth $0. That might be true or…
"Additionally, if the company gets funded, the very first thing that will happen is you will be fired or otherwise relieved of your position and they will hire an experienced CTO who will be paid a lot of money. This is the smart money move for them and a pat on the back for a job well done is all you will be likely to get." If that was the situation (and I agree, potentially likely) - but yet still an option for him…
The contract can be ignored. How's he going to fight it? He's been working for free and he's broke. He has more important things to worry about like eating. So a crappy lawyer takes his case on a 30% contingency. It's still an uphill road until he might somehow get something.
Never work for free.