[wakeywakeywakey]

Are you doing development? Is it just you two? What are they doing during this time, aside from having originally provided capital? Are they smart money? Do you need them aside from their money? Do they have connections, a network, or something else compelling they bring to the table? If you're sure you're going to raise a seed you could give them a larger cut of that "not too far away" as you said.

To answer your questions more directly:

  > 1. Is it reasonable for a Technical Founder to take a Median HCOL salary (due to strict financial constraints) while the Non-technical Founder takes €0?
  > 2. Does the "Fairness" argument (matching salaries) trump the "Runway" argument (survival) in early-stage startups?
  > 3. Did they waive the right to claim "unfairness" by joining the partnership with full prior knowledge of this asymmetry?

There is no "right" and "wrong" way. There is no "fair". It's whatever you can swing. You are partners, and if you want to keep it together you need to avoid building resentment, but it's also a business, and you need to bet on yourself. The "fairness" obsession is naive and it's exactly what slippery MBAs like to foist over devs who are zoomed in too much to value their time properly.

What's stopping you from getting a job and doing this part-time on your own, retaining all equity?

[throwawayround]

I’m doing all of the development and he’s handling product and business. It’s just the two of us. Now that we’re entering an accelerator, it’s basically all or nothing for both of us.

Maybe the better question is this: is it ethically acceptable to expect him to take 0 salary until seed without additional compensation, given that this is the only way we can realistically reach a seed round? In my mindset if he doesn't do this sacrifice he already loses 100% of everything.