A quick update on my Nadia… it didn’t flower at all this year, its third leaf. The adjacent plums (Satsuma, Early Golden, and Ruby Queen) flowered (and have mostly gotten nailed by the weird weather) so I don’t know why it didn’t. They are all the same age so that isn’t a factor, and since I am in NoVA, zone 7a chilling hours shouldn’t be a factor.
I figure I will give it one more year and if it doesn’t produce something next year maybe take it out. It has grown rapidly and is a good looking tree… but I do kind of want it to make fruit.