Depending on how thorough you consider a test, I've tested the Black 2 clean .nds file with my Super Card DSTWO and it works fine.
How did you get it to work? I've tried running it in patch and clean mode on my Super Card DSTWO with no success, even deleted my .sav file and everything. It always freezes before I get into the game. (Like when I would press continue when I tried using my save or after you name your rival when starting a new game. Also when in Clean mode it freezes when it asks me to name myself.) I have the lastest firmware, eos, etc. for the SCDS2.
To the person who would patch these things...I've encountered one bug in the patched version of Pokemon Black 2 while playing on the Super Card DSTWO. In the trainer card when you try to view the Medal Rally it always freezes. It's the thing that you go to when you click the blue circle near the bottom-right of the picture of the protagonist in your trainer card. It doesn't freeze when played in clean mode on the patched rom though,
but playing the patched rom in clean mode makes it laggy.
I've also heard a lot of people complaining about a bug in the patched version where it freezes during some Pokemon tournament or something like that. But, I can't confirm it yet as I haven't gotten that far.
EDIT*
I tested a patched rom in DeSmuME and I was able to access the Medal Rally (I tested it with the save file I'm using on the SCDS2)... So I don't know why, but it keeps freezing when I try to access it on my SCDS2.
Also, I've continued to try and get the clean rom to work on my SCDS2 with no success. (I downloaded a few clean roms from different sources too.)
EDIT**
I tested clean mode on the patched rom again and there's virtually no lag now... I'm not sure why it was so laggy before, but I think I might know. I can access the Medal Rally in clean mode on the patched rom too, so everything is fine with me for now. If I encounter any other bugs or abnormalities I'll post here.

Anyways, currently on the SCDS2 the Pokemon Black Version 2 Official US release AP patched rom will freeze when trying to access the Medal Rally if your playing it in patched mode.
Edited by xxmodnarxx, 09 November 2012 - 06:30 AM.