Tl;dr - to me, threatening to stick around as dead weight is your leverage. Your actual leverage may be something else. Work it out, use what you have to get what you want.
It might help to understand where this idea came from for me. This idea came from me thinking that, as I'm always rooting for founders on "Shark Tank" / "Makers Tank" ( whatever it's called ), to just take the offer, since they are beginning a journey, and the offer could take them to the next level, and they shall have many more chances to extract value from this down the line, whereas if they don't take it, to me anyway, their success seems less assured, while in your case, contrary to that, I thought of the inverse, where once you make the choice, you don't have any more chances to extract value. It's your last bet at the casino, make it count. So, in a way, I think this strategy I propose has something similar to the "martingale" betting method.