Ask HN: Doing non-core work to generate cash-flow: Y/N?

Let's say, hypothetically, there was a pre-MVP startup team consisting of a couple of hardcore technical software engineers and one non-technical, suit-wearing, business jargon-spouting, commercial/MBA-type, who were working on a software product. And let's say, hypothetically, that everyone was serving out their notice periods in their current jobs and, over the next six weeks or so would be freed up to work full-time on the startup. Clearly, in such a situation, pre-revenue, pre-funding, everyone's going to be living off their savings. And, given the product is software, the heavy lifting to create an MVP is on the technical side. So if, hypothetically, the non-technical guy had the opportunity to do some contract consulting work (in an area unrelated to the startup) and thereby generate some income for the company - enough to simulate ramen profitability - would it be worth doing that? The upside is that there would be some cash for expenses and salaries, which would mean that people wouldn't have to worry quite so much about how they're going to pay the rent when their savings run out. The downside is that one of the team (albeit the non-technical one) would be off doing something else 9-5, five days a week, and would only be able to contribute their input to the MVP in evenings and at weekends. Obviously, the non-technical guy would drop the consulting gig and switch back to focusing on the startup full-time when the MVP was ready and it was time to start finding customers, talking to investors, etc. Thoughts, opinions, anecdotes and cautionary tales welcome.