[carbonatedmilk]

Get them out, but let them vest.

Don't delay the decision - You've had performance conversations with them already, so this won't come as a surprise.

Tell them they're on leave immediately, and then pay them whatever they're owed in terms of leave, set their effective termination date for just after their vesting date.

Talk to the team, explain that it didn't work out, but that you're not the kind of founding team who will screw someone out of their equity weeks or months before their cliff.

The team will respect you doubly : For getting the under-performer out of their team, and for treating them fairly. This may sting a bit, it's your company and you're killing yourself to try and make it worth something.

Consider that the cost of learning how to be a better boss and not having made the hard decision earlier.

If you go the other way, you risk killing your velocity and losing the people you need.

[jmcminis]

In general the CEO has the ability to award equity however they want. It's fairly common for exercise windows to be extended, awards to be increased as a part of a severance package, cashless exercise to be allowed, etc. You may need to get sign off from the board, but that's usually easily justifiable.

As stated above, after that, the communication to the rest of the team is key.

[altgoogler]

I can't help but think this is the only sensible approach.

Persistant performance related issues are management's responsibility. It's unfair to withhold their vesting mere weeks from their vest date when management should've addressed the issue earlier.