Ask HN: Does my co-founder need to quit his job before we seek seed money?

Is it common for seed funds (like Kima15 for example) to expect co-founders to have quit their jobs before being approached? Or is there another way to do it that lets the fund commit to investing but on condition that the deal only closes once the co-founders have quit their existing jobs and come on board full time (with say a fixed time period for this to happen within e.g. 45 days)?

In my case, my co-founder wants to come on board full time but can't afford to quit his senior position at an existing well funded start-up until I have at least some guarantee that I can get a seed round together.