I want to build their product but they haven't got funding yet.
Unsure how common it is to take just stock/a mix/an agreed cash payment once funding happens etc.
Considering spending 20 hrs per week one of two chosen projects to spread my risk pre-funding, unsure if this is acceptable either, though.
Also, because life is short and your savings aren't infinite, set some metrics (X many users, Y much revenue, Z much funding, etc) to meet under some time horizon (3 months, a year, etc), and when that time point arrives, if you're not close to your goals, fold the company and try something new.