I'm a technical co-founder in a pre-funding company in a niche tech segment, working with two non-technical co-founders who have largely overlapping skill sets. I met them at a networking event and joined full-time on the project two months after they started it. We are all first-time entrepreneurs. As background, I previously worked as an engineer for a startup in the same tech niche for salary + benefits totaling about $150k (plus stock options).
We have all worked for no pay in my first six months with this company, although it has been agreed that I will receive an insignificant cash amount soon (<10% of market salary). I have sacrificed my time, health, and relationships for this company, spending almost all my waking hours working. I have remained committed to the company, turning down several very lucrative employment offers. To date I have produced a full working prototype that will soon be ready to launch to customers. Besides being the sole technical contributor, I have also played a significant role in product and business strategy and have brought in many contacts that have turned into useful advisors and key sales leads.
The twist is that in my first couple months with the company, I also applied to an extremely prestigious one-year academic program at a top university. It was my dream for years to complete this program, which will make huge connections for me and take my career to the next level in this industry. I was transparent with my co-founders the entire time about applying for this program, but while I didn't expect to get in, I told them I would defer it if possible (which turned out not to be possible). Long story short, I got in and accepted the offer. This is a program people do not say no to, and I am certain that it will in the long run increase my value to the company and bring in great connections. In the meantime I have promised to find someone to replace me as the main technical contributor for this time.
It ends up I'm going to have to start this program just before my first anniversary with the company. However, I intend to remain committed to the company as much as possible during the program and full-time again after the program. I initially signed a deal where my equity stake was much less than that of the other co-founders as a concession to the company since they didn't really know me coming in. The deal was that we'd re-negotiate after prototype completion, and I would have expected an equal (33%) share at that point if I weren't doing this program.
My co-founders have made it clear that they don't want me to vest any equity after the one-year cliff if I am going to "leave" for this program. I am OK with that, but I think that one year's vesting of a 1/3 equity stake (roughly 8%) is more than fair, and if I take less than that, I would like to receive significant cash compensation for it. I personally feel that that's a steal for them given the magnitude of my contributions. My co-founders, however, think that I should be left with only a miniscule percentage of the company and nothing else. That seems extremely unfair considering the massive risk and effort I've put in to this company (and will continue to put in). Who is right here? Am I already lowballing myself?