We had a finger dragonette come in once as a baby, mistakenly labeled as a scooter blenny. Even as a baby, this thing would've been a MONSTER scooter.
We kept it in a 300 gallon rock pool, and it seemed happy enough until it was about 6" long. At that point, it was starving in a massive system. It couldn't forage enough among the rocks to sustain itself. We tried switching it onto something prepared, but it wasn't having any of that. Thankfully, the aquarium at the zoo had a stingray tank tied into their reefs, and the 8' diameter ring of sand kept the finger dragonette happy for another 5 years beyond what we could.