Should I still give Revolution even if vet isn't 100% sure of diagnosis?

Our female mini rex, Brie, started with a little lump on the edge of her ear, and now she has lumps on her back rump area and on the other ear. We took her to the vet because we weren't sure if it had to do with molting or something else. Our rabbit savvy vet took some samples, but didn't see any evidence of mites. It will take three weeks to get the fungal test back. In the meanwhile, she said we could do a few different things. She said we could try Lotramin (the stuff for fungal infections like ringworm), or we could try to do a round of Revolution. We haven't done anything because we were still trying to decide, but the lumps seem to be getting worse and they are extremely itchy for her. I really think they might be cheyleteilla/mites and that we probably got them from our hay (which is Oxbow but seemed to be a bad batch this time around).

She is a house rabbit, and is separated from our other animals, but we do have a senior dog in the house that I wouldn't want to get them. So, if I'm wrong, and we do a round of Revolution, will it hurt her? She recommended the kitten dosage. How do you measure it to make sure it's the right amount? She told us just to use one kitten dose. The rabbit is 5.8 pounds.

Should we wait to try the Lotramin until we know for sure it's fungal instead of mites?
The lumps look like skin with a lot of dandruff and they are itchy. She said we can always bring her back and they can look at another skin sample, but I know we had a problem with mites years ago and one dose of Revolution took care of it all (along with massive cleaning of the cage area).

Revolution is quite safe. I would go ahead and use it. Even for prevention.
Rabbits however should be dosed higher then dogs and cats.
18mg/kg
Your bunnys about 2.6kg so dose would be 46.8mg ... very safe to round up to 50mg dose.

The blue cat one is 45mg/tube
So this might be the best choice.

The brown sm dog one is 60mg/tube

The pink box puppy/kitten revolution only has 15mg per tube. You would need at least 3 tubes.

my bun had some lumps on the tip of her ears for two years (I thought it was normal but when I got my 2nd bun I notice it's not) and the vet didn't find any mites on her but still gave her revolution just in case. she weighs 2.57 kg and I didn't use the whole tube on her. the vet suggested use the whole tube but I was too scared of overdosing so i put about 3 drops on the back of her neck and did it again in 2 weeks. There is no more lumps on her ears and she doesn't scratch herself as often.