There is sometimes the chance for WiFi games to be nerfed in the WiFi section after they're trimmed. Small explanation here:
The code for games is almost repeated twice on the cart/file, trimming cuts off the redundant code, which is basically always at the end of the file, however, some WiFi capabilities are stuck onto the end of some games, and from that, the WiFi may not work.
That was a description for an older trimmer however, and I expect the newer ones to cut through the code like operating with a finely tuned scalpel.
If you received the manual CD for the M3, there should be a suitable trimmer supplied.