[enigmatic0202]

Yes, extended exercise window is preferable, but that also means the ISOs have to be converted into NSOs, which are less tax favorable assuming an exit happens. So while flexibility is nice, it's not a free gift either.

What you can control though are:

1. Knowing your exercise cost in advance - sometimes you can negotiate for a bonus that can subsidize the cost

2. Getting a fair salary and equity cut based on the funding stage; even if you don't exercise all your equity, your package can at least be used in future negotiations: https://topstartups.io/startup-salary-equity-database/

3. Asking for the option to extend exercise windows if you choose, turning ISOs into NSOs