In my mind, an automatic climate control system, like those installed on W124, are automatic and does not require human intervention.
Except for the rare few time I switch my system to "defrost", it has been running on full "automatic' for 14 years and 390K without ever missing a beat. I still have the original R12 refrigerant in my system.
There is no reason to "play' with the temperature settings as it will not cool or heat faster, whatever its position.
Leave it alone.
jackD