[matchagaucho]

100% "shotgun" vesting is common in this situation.

Now, whether those shares are liquid or not depends on the RSU or options structure.

It's common for a Co-Founder to exit with 100% vesting, but the actual payout of those shares is contingent on a liquidation, funding, or revenue event.

Consider 50% cash now and 50% contingent on achieving $1M in ARR (for example).

You also need to consider your reputation in the industry. Framing this as "unfair" does not send a particularly good signal... especially since you terminated this person, who presumably took significant risk to quit a day job and build a company from scratch.