You're absolutely right, there isn't a way to do this as far as I can see either.
There is a way to send an analog value to be displayed on LCD when a new value is pushed, but that only gets you half of what you need.
The way things are now, you could set it up to turn the backlight ON but not turn it back OFF again.
With so many combination of inputs and outputs, it's hard to know if we have covered everything. Looks like we missed this one. Thanks for bringing this up. I'll see if this can be added.