Something tells me the stealth magnets don't have as influential a change as the actual driver used. It might not make the Arya sound any smoother either, since the stealth magnets were used first in the HEKSE, not the HEKV2, and from what I read the SE has a more peaky, punchy sound, similar to the Arya. Then again, they were also used in the Susvara, but that's another monster altogether.
If I had to guess, I would say the smoothness in the HEKV2 has more to with tuning and actual driver used, since soundstage is so much wider with a clear step up in imaging. But I could be wrong. I would be pissed I spent so much money on these, but I could be wrong