When I was a small boy, I used the term Aunt when speaking to, or about, my mother's sister and my father's mother's sisters and several other ladies (apparently unrelated to me but) well known to my parents.
I assumed it was another one of those terms of respect for adults that you learned to use through practice and occasional reproof.
The idea that there might be formal rules for allocating this honorific across generations simply did not occur to me. So when I had children, they referred to my (actual biologically-related) aunt as their aunt.
We did not even consider the use of any generation-indicating prefix.
Thirty years on, my son's children know that they have many aunts including my daughter, my sister and my mother's sister. As a genealogist, that now seems just a little untidy and potentially confusing. So the recent article by Judy G Russell on the apparent inconsistency in referring to a pair of sisters as grandmother but great aunt struck a chord.
I happened to mention this to the 2xgreat aunt of my grandchildren (that is, my aunt). She had no particular opinion on the relative genealogical efficiency of the choice, but did observe wistfully that it might have been nice to be called "grandaunt".
What a shame that this conversation came more than thirty years too late. What may seem to be mere technical terms can carry surprising personal significance within families.
I need to remember to assure Aunt Joan that whatever we call her, she has done (and continues to do) a GRAND job.