Im interested in the temperature variation and taste thing. I have my bezzera at about 90 degrees which is the maximum temperature manufacturers of Bezzera and Cimbali recommend.
Mind you unless you are there measuring everything with a thermocouple you really are relying on the readout on the Minore being correct. As you know it is an offset reading based on what they calculate will be the pour temperature. I think that this is factory set at six degrees although you can change this.
I certainly find 90 degrees works just find although the variation will be from 88 to may be 91 degrees over the boiler cycle.
I also have my group pressure set to 8.5bar and I check it now and then with a pressure gauge built into a special portafilter. I bought this from coffeeparts com.au. I think there is an OPV adjustment for the Minore as I remember seeing a diagram of the adjustment for it. It might be reasonably obvious where this is if you have a look inside as the OPV has to control the solenoid to divert the flow to the drip tray in event of overpressure.
Bezzera machines are designed to balance an optimal environment of approximately 8 to 9 atmospheres. If the pressure begins to exceed that level then a special valve (back pressure relief valve) opens and diverts the water to either the water reservoir or the drip tray. This serves at least 3 functions: it protects the pump from excessive pressure buildup, lessens the likelihood that the coffee will be over-extracted and prevents the machine from blowing coffee all over the counter top! In addition to keeping the pressure balanced, the machine features a thermostat, which controls automatically the brewing temperature to the optimal 86-89 degrees Celsius.