Well, I just got the BluRay from Netflix, and though I haven't had a chance to watch the whole thing for-real, I couldn't help but jump to "Field Test" and check it out.
The first thing I noticed was just how frickin'
young they really did make Bruce Wayne. The next thing I noticed was that it was so very, very Bee-Train-y.
There was a bit of a mental disconnect hearing Kevin Conroy's voice with what could have been a cross between Carrouseur and Orpheus from Meine Liebe -- I've watched so much of the classic Animated Series, and he looks nothing like what I'm used. But listening to the commentary, it sounds like they wanted him younger on-purpose, so there you have it.
The commentary had a couple of "I think this is the best [whatever] in the movie" for different sequences. It also had one line that made me laugh -- when Batman shows up in his new armor, one of the commentators pointed out that he was the first "Gatchaman-Batman". And sure enough... ! And seeing as Mashimo's first claim to fame was way back in the Gatchaman days, that was probably on-purpose, maybe even an in-joke.

In the credits, Mashimo is the segment producer, and Bee Train is definitely the studio. Not to mention that Bee Train was tweening just about every other episode (except for the Korean one I think) -- in fact, it looks like just about every single studio and shop in the whole country wound up with their fingers in this. Makes sense, because it's rather a lot of drawings to go through.
I haven't quite figured out how to get screencaps from my BluRay player software yet, but I'll see what I can come up with later.