Unicode request for Latin subscript letters
This is part of the document I was able to find on the Unicode official website.
Honestly, since English is not my native language, I didn't really want to read it, but it might be helpful.
These characters seem to have been added with very specific purposes.
This is just my personal opinion, but I have looked through all the Unicode character charts before.
Among them, there were cases where only some Latin characters were added for specific purposes (such as mathematical purposes),
but later on, all Latin characters were added.
There were also cases where newly added characters were assigned to separate areas,
and cases where all characters were assigned to separate areas. (In these rare instances, duplicate characters with the same shape occurred.)
It might be added later as you wish, but it's not definitive because the Unicode space is finite.
Even if characters are added, it will take quite some time for fonts to support them.
Who knows, I'm not even the person in charge. Haha...