Hi Mark,
I guess you work in manual mode? Switch to aperture priority mode and live view will be fine. The disadvantage is that the camera changes exposure time dependant on what it thinks is right. You have to watch carefully to get the exposure you want.
But this is a problem you have with every lens that has no chip to tell the camera which aperture is set (not only old manual lenses - even the new Schneider PC-TS lenses for about 5000,-€ do not have a chip which is ridiculous in my eyes). The chipping of the adapter could be a workaround (I never tried but I think Dandelion makes such chips). You can program them to tell the camera all it needs to know. Then liveview should work in manual mode too. But I am not sure if they fit with one of the available Contax to EF adapters.
I am curious: does anyone here use such a chip with the PC-Distagon?
Marc