At my current age of 60, if the mini-skirt is more than simply covering my butt I wear them, many times have tights under them so in one sense of the word it's akin to wearing leggings with a top to cover my rear-end.
For those mini-skirts which barely cover my butt, think the last time I wore one was around the age of 40 and that was acceptable when out at night to clubs but not in day to day life. Mini-skirts for day time, I stopped around 30.
One thing I learned around the age of thirty was going to a professional to learn how to pass in public and she pretty much said the main rule of thumb was (besides her recommendations) to conform to how others are dressing in their day to day life at my age. I believe this helped me before transitioning and simply dressing as a female and I passed with zero issues while dressing in mini-skirts and high heels drew up due attention to me.