My Chihuahuas have been sleeping on the heater vents for years. We had a big house, and Spokane is cold, so any dog that wanted one could claim its own heater vent. But of course there were squabbles.
Now, in this smaller space, the powerful heater makes the whole place warm instantly. One thing they don't tell you about a big house is that it can take a couple minutes for the hot water to reach the faucet, and you'll have lots of cold spots even with so many vents.
So, none of the dogs have an interest in the vents except Zoey. She picked one out and she keeps looking over at me to get my attention. Every time I look at er, it's like she's trying to tell me
"Here, Pet, here's where the warm comes out. We need to both sit over here, Pet."