Some Tesla investors are worried about whether Musk can focus adequately on his role as CEO of the world's most valuable carmaker now that he has been running Twitter Inc after a protracted buyout that at one point he tried to scrap.Antonio Gracias, a longtime friend of Musk who was also a Tesla board member from 2007 to 2021, testified that there were conversations of finding an "administrative CEO" who oversees sales, finance and human resources "so Musk can focus his time as chief product officer which is his most vital function."Musk, who is CEO of Twitter and rocket company Space X, among others said, "Frankly I don't want to be CEO of any company."On Monday, Musk said he had worked through the night at Twitter's San Francisco headquarters and would keep "working & sleeping here" until the social media platform - which he recently acquired for $44 billion - was fixed."AS LONG AS I CAN BE USEFUL""It's worth noting there's a light year gap between identifying someone and having that someone take the job," Tesla investor Gene Muster tweeted after the news."