If you do high-end colour grading, then 4K is a huge boon for secondaries. It is also a huge boon for razor-sharp reframes. Just because you do not understand a value doesn't mean it doesn't exist.
Reframes over 133% will not be that razorsharp. Remember that RedRAW is still compressed quite a lot and there are lenses that don't resolve even HD (mostly anamorphics and the corner res of them). And I don't really see how 4k is a boon for secondaries. Explain?