S.BUS switch channels 17 and 18

I have a T18SZ. I can use channels 1-16 just fine, but I am not seeing the ability to use the 2 switch channels. I see that the Linux HAL has the code to use them on the master branch, but CubeBlack/ChibiOS does not. I might be overlooking something. Are there plans to use the sbus.cpp decoder on the ChibiOS boards?