Oh, I'm crossing my fingers too, for you and Leroy and hoping for a speedy recovery and some definitive answers.
She thinks you should run an ABV test if you haven't done so yet.
Phenobarbital can be a really heavy drug on birds and the dosing can take some time to get it right. If you are having new symptoms or having questions about reactions call the vet tomorrow and ask before the weekend arrives. Also ask the vet about weekend hours and emergency services in case something happens over the weekend and he needs to be seen. While they are on the phone ask your vet about DMG, he should be able to answer your questions about that as well. If it were me, my vet would have recommended it already but ask so you feel safe about it.
I'm sorry Audrey, I don't agree with your vet. I know that you have MUCH first hand experience with this, but I would exhaust all other possibilites before testing for Borna. JMO