John "Shambler" Barrett has released ONSPlus. ONSPlus contains a lot of fixes\adjustments to both Onslaught and vCTF. A complete list of fixes, and other information, can be found here
ONSPlus can be installed as serveractor or mutator and, if I recall correctly, is whitelisted so you server will remain a "standard" server when using this addon.
You can get ONSPlus from BeyondUnreal
or directly from us