Exercise Deadline for ISOs after Termination I will not promote

I will not promote. Does every company pretty much have a deadline for exercising after termination? I am a few months into a company and am burnt out and am thinking of quitting what is supposed to be a unicorn startup before my first vest. It looks good on paper...and has the numbers and profitability to continue on a good trajectory. But I can't help but feel like it's a pressure cooker that's about to blow up. Everyone is burnt out. I am realizing now that the people that have been here for many years are in a predicament where if they quit they have to spend tens of thousands of dollars to exercise even though there have not been any exit opportunities up to now. So my question is, does every startup have the exercise deadline after termination? I feel like that's just a trap to keep people onboard and stress them out with a ridiculous unmanageable amount of work.