SETTINGS error handling

Section 6.5
   single SETTINGS frame MUST NOT contain multiple values for the same
   ID.  If the receiver of a SETTINGS frame discovers multiple values
   for the same ID, it MUST ignore all values for that ID except the
   first one.



I'm wondering why the text proscribes error handling of MUST ignore in
response to violation of the MUST NOT send provision. I'd rather my
implementation be strict and enforce the MUST NOT send via PROTOCOL ERROR
when receiving this. The kindler gentler days of being liberal in what we
receive have sailed. There is not yet an argument for backwards
compatibility to not do that, but if I did so I would also be in non
compliance.

Can we either change it to PROTOCOL ERROR (preferred) or just be silent on
handling of the error?

-Patrick