Need advice - Renegotiating my contract as a founding engineer (i will not promote)

( I will not promote) a little background: I have a PhD in computer engineering and four years of experience at a FAANG company. The startup’s CTO, who was my former manager, reached out to me about joining as a founding engineer. The CTO built an MVP that helped secure $5M in seed funding. Given my deep expertise in research-heavy, deep-tech development, I was brought on as the first hire to drive the core algorithmic work, which forms the backbone of the company's value. After negotiations, we agreed on an offer that includes a 40% pay cut from my previous salary, and 2% equity, with plans to hire 2-3 additional engineers to support software development. In the 2 months in my role, I have basically built the whole system by myself, given they have been struggling to hire other people. That includes all technical and AI research related tasks. As we prepare to onboard our first client in May, and being a lot more aware of the type of income it would generate to the business (5m in the first 6 months), I would like to renegotiate the terms of my contract to include either profit or revenue sharing. At some point, the CEO and I discussed adding a growth element to my compensation. While he was adamant about doing it only after our Series A funding round, I now think that client onboardings or revenue is a better metric for that type of compensation structure. On one hand, I would like to do it in the next month or two, since this would give me the most leverage and would put the most pressure on them to accept. They won't be able to hire anyone else before the client onboarding if I leave, especially considering the low salary and tight timeline. On the other hand, putting this much pressure so close to the deadline might change their perception of me. Especially considering the current CTO told me that he would like me to replace him in the next year (again, this could be all talk). In the same time, waiting after series A funding would also remove any leverage I have, and reduce my negotiating power. What do you guys think?