Like many start-up Founders, I have not quit my day job. I will be thrilled when I can, but for now having to work double shifts is the only feasible way to make ends meet. This is even more true having gone into debt to develop a product.
I have reduced my day schedule from 5 to 3 days a week and fortunately, my long time employer supports the entrepreneurial effort. The day job is an additional source of steady income and although it squeezes my time, it decreases the odds of my biz prematurely going under because I don't have all my eggs in one basket. That's my logic - not sure if that's investor logic?
When an investor evaluates all the metrics that go into a new venture, in addition to ROI they look at the ability of a Founder or management team to be fully committed. I am, but end up working 70 hour weeks between the two jobs.
Do you believe investors strongly prefer a FT Founder (s), or is working a day job until getting to positive revenue acceptable?
Investors clearly prefer and demand a full-time founder. But it doesn't mean you should quit your job yet. It looks like you are in a great position, because currently you have infinite runway. This is extremely valuable: it gives you the time to iterate and find market fit. Once you call tell that your startup is starting to take-off, then quit, accelerate and pitch investors.
I understand your situation as mine is somehow similar. Well all I can say, include this into your pitch to a potential investor as an argument why you want to get funded - so you can commit to this full time and being able to get by till you business kicks off. Good luck.
If you can keep ties to a steady job, and build the company, I think you're in great shape - because it's the viability of the product and the significance of the traction that'll convince an investor more than impoverished heroics. The results will count for a lot.