Extending Post-Termination Exercise Window

Hey everyone,

Does anyone have expertise or experience on extending the Post-Termination Exercise Window?

I'm especially interested in the tax implications for both optionee and the company for extending this window. I know that the normal window is set at 90 days due to tax implications that apply specifically to ISO optionees. I think but am unsure that NSO optionees don't have these tax implications, which would make extending their exercise window a lower-effort endeavor for the company (assuming we accept these options return to the option pool later).

I know this doesn't replace legal or tax advice, but wanted to do an early check to bolster my own background knowledge before I seek counsel.