Has anyone modified a Yamaha WX-010 wireless speaker?

I'd really like to add an aux input so I can run them as a stereo pair from an Apple Airport Express.

Aside from them only being 2.4GHz and AirPlay 1 capable, when used in the Yamaha stereo paired mode they have a terrible time lag from the other speakers in my system.

Just wondering if anyone has done this successfully?
 
Sockets do seem to be finding their way on to the hitlist of what to cut from the budget. I've heard some manufacturers explain how this is doing us a favour. 😕

Any thoughts on how you want to do this.. tap into the board to add a socket, measure the response and convert the speaker to passive, active even, or add an airplay module with line in?