Interested to know: when you experience that, have you addressed it directly and said that you have an issue with it, and want them to stop? If so, do they try to pretend they aren't doing it? Or do they apologize and own up to it? Or what? I've been on the interviewer-side, but haven't run into that. I would absolutely see that kind of thing as an ethics violation; like paying someone else to pretend to be you for the interview process.

Personally, any time I have ever been the interviewee, I write up notes for things to cover during an interview, or list a few common problems, etc. I've dealt with in the past, but I would strongly prefer to share my screen with them so they can see I'm not getting "assistance" from an LLM or whatever. I just personally get very, very stressed when I interview for a job. Having a simple set of notes helps keep me on track with covering XYZ.