Not part of Founder's Pledge, but AIM did consider quite a few models like this when doing our founding-to-give program. Our pledge is higher, with 50% above $1M being the minimum. Right now, both ours and Founder's Pledge connect to individual giving (aka the profit the cofounder would take home personally) instead of, e.g., committing the company itself to donate. They are also both pretty "clean" models as they do not require a heavy administrative burden to take stocks, investments, deal with dilutions, etc.

Net, I think both models slightly benefit the companies with almost no impairment to them, which I think would not be the case with heavier models (e.g., directly taking stock, requiring company donated profits, etc.). Our reason for going this way was:

1. Our sense was that typical investors are far less excited about companies that would have to donate/take ethics into account and somewhat less excited about those who have given away any sort of equity
2. Our sense was the founders typically are founders due to wanting control, so the more control we asked for/restrictions we put in place, the fewer high-talent founders would be keen
3. The admin cost for this is pretty intense, especially for an NGO, so we would have to think that it would have a major upside vs e.g., someone taking a 50% pledge and donating via their own DAF or foundation.

Not specifically but in talking with investors, it was made pretty clear that they would not be happy to invest if their profits would be hampered from donations and we could only do it with our own money. Frankly, I think that makes sense. You get to donate your own money, not others. If you're in a spot where you can be picky with investors, you can just get a higher valuation or better deal terms.