Just uncommenting this line and commenting out the 0x05 line above is not enough to get interleave working.  I also modified the test application to include the line: dolphiimote_enable_capabilities(wiimote_number, dolphiimote_CAPABILITIES_EXTENSION|dolphiimote_CAPABILITIES_MOTION_PLUS)

This does properly cause operation to enter thepassthrough function, but does not enable it properly.

I was able to get it to work sometimes by modifying the wiimote_capabilities::type enabled_capabilities and wiimote_extensions::type extension_type while debugging to force both functions to be enabled, but I couldn't find a way to consistently make it work.  Besides that, there doesn't seem to be a way to determine whether a nunchuck (0x05 command for interleave) or a classiccontroller, or drums, guitar, etc. (0x07 command for interleave) is connected without first enabling the extension and disabling motionplus.

However, because the discoverer seems to determine capabilities asynchronously, I wasn't sure how to proceed, so I just left the above line as a placeholder for future investigation.

I was also able to verify that Nunchuck interleaving also does not work at this time.