After having had the opportunity to try the V3 Sound Sonority XXL and MB Music PRO.DX expander modules, I believe that this module wins the gold medal by secondment (just to be on the Olympics theme). Without taking anything away from the other two mentioned above, but I think the overall sound quality is decidedly better, it fully supports the GS/GM format (vA2 set in GS mode), I don't know about the GM2, I would have to do some tests on it. It's basically a Roland clone expander with lots of interesting sounds. Too bad there aren't many demo videos around.
X-light 4 (https://www.m-live.com/x-light-4-2/)
DEMO (https://www.youtube.com/watch?v=_z-MHYYwlAU)