My findings were that C-41 was usable at room temperature (Rollei Digibase) until the chemicals go oxidized, sooner or later.After a three year break from C-41, I did a roll of Portra 400 today, using the room temperature technique. Scanned RAW with Nikon 9000, and ColorPerfect (in PhotoLine, not PS) used to invert. All had a bit of extra purple that had to be adjusted with temperature and tint. But it was quite easy, and takes longer. Perhaps the next roll should be done at 102ºF so I can compare the colour casts.
Scanning can compensate for color casts.
I thougt I could do Tetetenal E-6 using same principles. But I could not get decent results from E-6.
In C-41 there is not so much something as color cast