BT passthrough is more than a week old; I actually started working on it in late August, the PR was submitted in September and merged ~27 days ago.
That's unfortunately a known issue. These two games spam the adapter with commands repeatedly, and there are adapters which can't keep up with that. It's less severe in Skyward Sword, which only does that before you get in-game, but NSMBW does that during the whole game, and this can cause connection drops or stuck remotes.
(Technically, the game is sending 120 commands per second, and it's expecting them to be acknowledged by the adapter. If this doesn't happen (because the adapter failed to keep up), the game will keep waiting for a reply until it times out, and during this time, it'll stop transferring anything else from/to the adapter)
Emulated Bluetooth shouldn't be having this issue though…
That's unfortunately a known issue. These two games spam the adapter with commands repeatedly, and there are adapters which can't keep up with that. It's less severe in Skyward Sword, which only does that before you get in-game, but NSMBW does that during the whole game, and this can cause connection drops or stuck remotes.
(Technically, the game is sending 120 commands per second, and it's expecting them to be acknowledged by the adapter. If this doesn't happen (because the adapter failed to keep up), the game will keep waiting for a reply until it times out, and during this time, it'll stop transferring anything else from/to the adapter)
Emulated Bluetooth shouldn't be having this issue though…