Yes it WILL cause crossover, and other problems too (such as loss of saturation, if gone too far), but there is a but...
The crossover (& other errors) might be small enough that it is not visible in most images without side-to-side comparison with the exactly same scene processed normally.
And, the crossover will be small if you deviate just a little bit. A few degrees C.
Furthermore, "averaging" is an acceptable procedure; If you start with 103 F and end up at 97 F you are having a development very near to standard development at 100 F. IIRC, even The PE has mentioned this averaging thing .
The point is, why process incorrectly when you can process correctly? There might be some point to it but it's hard to imagine what. It's extremely easy to set up a water bath. Without a water bath, you may really risk running so far from the correct that the problems might get really visible.
You are making a good point, anyway; it's unnecessary to be scared about developing color. You will get good and perfectly usable results unless you screw up very badly. Even with a sloppy control, you probably exceed a typical minilab level.
Last edited by hrst; 04-17-2012 at 03:31 PM. Click to view previous post history.