In an ideal world, yes, that is how it would work.
As for the sudden change, it was due to the start of CASP which is a time critical even (runs May-August). You mught not be able to completely trust the thermometer throughout the rest of CASP but we will always post a warning on the News page and this forum several days in advance of changing proteins. This is because we don't know when new CASP proteins will be released so we have to go with what they give us. Sorry for any inconvenicence.