other things they might do on a light piston twin
- reduce current in pitot and stall heat circuits, making them warm enough to check on the ground and prevent icing, but not too hot to avoid burning them up without normal flight airflow
- Mode S transponder switching between GND and ALT mode (can also be done by coupling to GPS groundspeed)
...but I'm with Bose, on a BE76, most likely gear retraction preventition