You’re absolutely right. It’s highly unlikely they’d rule in his favor. As you said, that would give any president absolute power and that’s not agreeable to the court who, after overturning Chevron, will wield a lot more power themselves.
I hope they refuse the case. It would have been smart for the judiciary as a whole to do that a long time ago. Let trump face trial while they still had another viable candidate in the race. However, the strategy in all of his legal fights has been to drag this out as long as possible in the hope that he becomes president and it’s all null and void. Thus allowing him to never face trial and the court to never rule either way.