I have an older (but not old) Mini, and I find it almost unusable, as screen elements don’t scale up. For example, Safari browser buttons are stupidly small. Is that still an issue with the Mini?
I am not sure I understand what you mean by the scaling issues, so, I guess, no? I have the 6th generation. The problem I have (and I do not see getting improved, somehow) is that applications do not care for it. Many times I have to turn it to landscape for some more room to fit everything.
Most applications feel better on landscape, but then you lose vertical space. Affinity Photo 1 is very guilty of that, having buttons overlay each other on the left.