Apple’s engineers have toiled for years on a massive foldable iPad. A 20-inch display that unfolds into a portable workstation. But now, as John Ternus prepares to step into Tim Cook’s shoes as CEO on September 1, this ambitious hardware effort hangs in limbo. Mark Gurman laid it bare in his latest Bloomberg Power On newsletter : “The foldable iPad is a real thing being developed behind closed doors.” Yet. It may end up as an experimental prototype that won’t see release. Ternus championed the project during his tenure as senior vice president of hardware engineering. He’s been with Apple for 25 years, overseeing iPad evolution from its 2010 debut into a productivity powerhouse. Sources describe him counting screw grooves at midnight, pushing for innovations like LiDAR only on Pro models to protect margins. The giant iPad fit his vision. A super-sized screen for creators. But practicality snags emerged. How do you type on it effectively?…