I think you call his bluff, play chicken with him. See what he comes up with as his terms to the agreement, read the contract, have lawyers check it for loopholes and it they find one, sign the deal and exploit it.
Then donate the money to another foundation.
At some point I’d be willing to bet he would back down and not follow through, but anybody that is in a position to call him on his bullshit should do it
They could make a small screen phone, but thicker to make more room for a bigger battery.