... but I feel uncomfortable faking it in person to people -
"Feeling uncomfortable" will be picked up by the interviewers and it will raise suspicions. The solution is to find ways of not feeling uncomfortable!
I've approached interviews with the attitude that I am interviewing the company as much as it is interviewing me. Since I like finding things out, I enjoy finding things out about the company.
I regard an interview as a reason to blow my own trumpet a little - "look, I've done all
this", and "now, come on and ask me interesting questions about it". Intellectual to-and-fro is fun.
for example, I have designed boards with both analogue and digital, but I would not be comfortable saying I had experience with mixed signal board design, because I realise that in almost every case the requirements on a commercial design are far more stringent than what I am designing.
You haven't got experience of most things, so of course you shouldn't claim experience you can't justify! If they expect experience of Frobnitz v2.3, then the job will be limited.
OTOH, you should make them realise that you have easily picked up experience of new things in the past, and will do so again with them. Lack of experience is not a problem! Attitude can be a problem.
Interrogate them to find out what they want
and why. Draw on your experience by saying "oh, that's like X in my past". Then ask questions about alternatives that you guess might be relevant - shows initiative.
It's true that I could reveal less about the limits of my experience.
Let them ask about the limits of your experience, and then be open and candid.
You can tell them about your limits, provided you find a way to indicate that
in those circumstances you made the best choice.
You can also say "I haven't done X, but I want to in my next job".
Overall: being interviewed can be fun, if you approach it as an intellectual exploration
Oh yes, the first few interviews you have will be poor - it takes time to remember how to be interviewed. Solution: have a few "sacrificial" interviews for jobs that aren't important to you.