I've never seen that. Randomised per sitting yes. Within the same sitting no. Usually for important exams the desks are far enough apart.

It was done regularly in my highschool in the 2000s, there'd be two or three versions of the test and they'd be distributed randomly. We'd know which one we got because of a label in the corner, which was also how they used the right key for grading.

It'd surprise me if such a simple mitigation wasn't done for more important exams...

Medical licensing exams in the US are randomized within the same sitting, even having two examiners in the same room receiving entirely different questions (not just random question ordering).

I've had plenty of professional and academic exams with multiple different versions of the exam with the questions scrambled. I think almost all of my Bachelor level science courses were provided in that way, as well as multiple Bar exams.