You might find this 1942 war-time article about hovers interesting. They are certainly not new.
A few people on this forum mention the hover as a way to take care of chicks but you’re right, I don’t recall any thread that really explored them. I mentioned it just a few days back but I don’t use one so I can’t give any advice or details based on experience.
I think a hover does one thing very well, it provides an area warm enough while letting other areas cool off so the chicks can self-regulate. I do that with my heat lamps, heat one area of the brooder while letting other areas cool off. There are other methods that do the same thing. That takes all the stress about keeping things the right temperature away. Make those chicks do the work.
If you read that old article they mount the lights on the sides and face them across the brooder, not mount them on top and point them down. I haven’t looked at any articles newer than 1942 so I don’t know if that advice has changed. I like the dimmer switch idea but you might want to look at a smaller wattage bulb also. At least have one handy to have a bit more flexibility in managing it.
The only problem I can see with the hover is that you might have a lot of trouble seeing what is going on underneath. Say a chick dies under there, how would you know? It should conserve heat really well so yes, it should cut your electricity bill.
Maybe you can start a hover revolution on here. Good luck!