[pwdisswordfish4]

These are false/misleading statements, not questions:

> I remember something that previous versions were for webapps only.

> I remember that OAuth forced the user to include client secret in app's binary.

This is not actually a problem with RFC 7636.

[self_awareness]

You could spare your answer, since it's not providing any information at all.

[pwdisswordfish4]

Ruling out the truth of something is information-free, and mentioning an RFC by ID is information-free. Got it.