I don't mean to be a pest. I just want to make sure we are understanding each other.
I understand that I have to add kcfinder myself. I'm wondering if it is possible with limited modification, to alter one or two extension files and get the extension GUI (The site file manager configuration), to look at the new file browser instead of KFM. I'm not sure how much the WA extension files interact with KFM outside of configuration.php.
If it is only configuration.php, perhaps a slight modification is possible to get it to look at config.php of kcfinder instead.
If we're connecting, and it can't be done easily, that's fine. I just wasn't sure from your response if we were connecting.