A group of OpenAI executives and investors racing to get Sam Altman reinstated to his role as chief executive officer have reached an impasse over the makeup and role of the board, [...] Altman, who was fired Friday, is open to returning but wants to see governance changes — including the removal of existing board members, said the people, who asked not to be identified because the negotiations are private. After facing intense pressure following their decision to fire Altman Friday, the board agreed in principle to step down, but have so far refused to officially do so. As of midday Sunday, the board had not resigned out of concern over who could replace them, and were vetting candidates, one of the people said.