As a generalisation, most of the normal split Air-Conds that we see, do not have case heaters.
I have only seen them on some larger US products, where Sub-Zero is the norm.
Being in Sydney, that might bias what I see..
Were I at Cradle Mountain or Jindabyne , it might be different.
Needless to say, if your RAC (Reverse-Cycle Air Cond.) is turned on by a remote control, then it does draw power on standby, just like every other "Electronic" appliance. How many people actually turn their Fisher-Paykel washer off when not in use ? If you have one, feel the warmth in the control head !
If you did have a case-heater in a bigger unit, I don't think I would hesitate to disconnect it , in any but the colder areas of Australia.
In the least, you could fit a new switch, so that you could disable it in summer, and turn it on an hour before using the RAC in winter.
Something to watch, for those who have the big 2 door refrigerators...
Many have Mullion-Heater... Door Jam heaters, intended to warn the metal at the seal..
The fridge-freezer is real cold on the inside.. The cold is transmitted through the skin at the seal and for an area near the seal, it gets cold.
On humid days, condensation forms and will even run to the floor forming pools.
The heater is designed to selectively heat these area of possible condensation.
Problem is that they typically draw 60 to 100 watts -- Continuously !
Most fridges use the hot-gas from the compressor to do the same job, but as I said , some of the yank products still have them, and have a small switch inside to disconnect it for low humidity times.
Be sure to turn it off , for as long as you can.