I tend to agree with you about pre-scanning the arguments to find options. But at this point, our options to change the code are limited. The last time I looked at this (and it's been years), I came to the conclusion that the argument pre-scanning was sufficiently baked in to argparse that a separate traditional" mode was better done as a separate library.
But I lack the time and energy to research if there's an existing third party library that's acceptable, what it would take to enhance optparse, or write a new library.
It sounds like what you want is optparse, but with help in processing positional arguments. Is that a fair statement? Or is there some other feature of argparse that's preventing you from using optparse? I know for me it's help with positional arguments.
I think at some point we need to close this bug, because I don't see a way of modifying argparse to do what you (and I) want. paul.j3 explains several times in his messages on this thread that it's just how argparse fundamentally works.