NOT A TEACHER
(1) As has been stated, you are obviously an advanced student.
(2) I do not pretend to understand your question.
(3) I can, however, recommend a book that discusses this matter:
The King's English, by the famous Fowler Brothers. First published
in 1906. Reportedly a sensation among people seeking to speak and
write "correct" English. Some people nowadays feel that certain parts are
almost impossible to understand; others consider the Fowlers --
especially Henry -- as "our leaders" in English usage. If you can
get a copy, look for provided in the index.
(4) I do not pretend that I understand completely what he is saying, but
I think that you would really enjoy it and profit greatly. For example, he
Provided is a small district in the kingdom of if [Nobody writes like that
nowadays!!!]; it can never be wrong to write if instead of provided: to
write provided instead of if will generally be wrong, but now and then
an improvement in precision.
(a) The brothers then continue to explain the correct and incorrect use
of provided, with quotations from literature and from The Times, which
(at that time) was the newspaper of the elite that ran the country.
You will be entranced by the brothers' explanation, and I am sure that
you -- unlike me -- will understand and relish every word.