[aoloe]

As far as i know it's (very) hard to do correctly.

There are (small or big) differences among languages and it is not always obvious to detect ,if the quote should be converted at all, if it's a left one, or a right one.

As a reference, this is a Python Script trying to do the conversion in Scribus:

https://wiki.scribus.net/canvas/Convert_Typewriter_Quotes_to...

There is also an article by the author of the script, explaining his work and pointing to at least one common case it cannot handle:

https://opensource.com/article/17/3/python-scribus-smart-quo...

Putting all this logic in a font might or not be something your really want...

But I 100%: this should be done at the font level... and hard replacing characters is not a good solution.