@fizzboy Glad to see that this does, in fact, work with 3rd party bindings. I have implemented this with the native binding for the next update, and provided an L:Var, but using 3rd party binding applications will always be more reliable and flexible.
The issue with many of these native bindings, btw, is that Asobo added them to the list of inputs, seemingly without realizing that many of them require input values, like your 190 above. Without any way to provide this input value in the native controls UI, I believe we're just sending a zero, so the flaps never move...
Also, just to make sure, did you have the engine running and the cabin warmed up when testing the flap gauge? On the ground, it's very sticky, but once the cabin is at a comfortable temperature and the engine is running at flight RPM, it should move pretty reliably, or at least arrive at the correct position after a second or two without needing to tap on the glass.