It's not that the Request class is supercomplicated. The code is relatively straightforward, so it should be easy to fix if anything comes up.
And only months to years later distributions would supply any user with the fix in a new version of Pike!
While I have not yet had time to look at your changes, on a very general level I agree with Bill, "we can fix it later" is not a good argument; with something as prominent as Protocols.HTTP we should certainly develop the confidence that a change is not going to have negative impact in the field before considering to include it in a release.