if I set the heating curve so that it has 20 °C with fully opened thermostats, I can only increase the room temperature via the heating curve, right? That actually means first lowering the heating curve so that you reach a maximum of 20 °C and then raising the heating curve again a bit so that the thermostat still has some room to move upwards? Otherwise, I wouldn't need thermostats and would just go to the utility room to adjust the temperature.
For example, we have 23~24 degrees in the bathroom and 21 to 15 degrees in the other rooms, and yes, the temperatures also hold when you close the doors.
How much do you save percentage-wise through this fiddling?