Watch out for the version of kdelibs you need to patch with these modifications. When I made them I was working with a pre-3.1 CVS set of kdelibs but I recall problems when later trying to use these patches with 3.0.x release versions.
I think that one of the problems is due to viewport handling in kdelibs/kdecore and whether that was fixed at some point during the release cycle. Certainly, if you find that the patch is trying to fix something that isn't broken then you'll know why!
Good luck, anyway, if you do decide to try it out!