Scotland

For sure, most are fine with it. But as a teuchter I did find quite a few struggling to understand my accent, which is pretty mild, and I'm pretty sure making fun in hindsight. I socialised mostly with other Scots as a consequence.

Well, that sounds unfortunate, but it also sounds like at least some of it was stuff you were thinking (possibly correctly) might have happened rather than knowing for sure it did. And if "most are fine with it", that doesn't really explain you socialising mostly with other Scots.

I'm from Fife, have a bit of an accent, occasionally had to clarify for someone who didn't pick up what I said, but never found it to be a serious issue at all.

And it wasn't like I didn't have to ask for clarification myself sometimes. I had friends from Manchester, Liverpool, Norwich, London, Northern Ireland, the west of Scotland, Germany... At some point I probably asked all of them to explain something I hadn't caught, but not in a way that implied criticism or judgement.

Don't get me wrong, I was very aware of the whole "yah" phenomenon, but it certainly didn't put me off hanging out, or getting on, with people from all over the place, including some of those apparent "yahs" who often turned out just to be perfectly decent young people who happened to have what we might consider a posh accent, and found themselves in an unfamiliar town surrounded by a populace which in many cases was actively hostile to them, just because they were English.