@joncoughlin Just curious, did you ever figure this out? I'm currently working on the same issue, using Axis and Ohs. I tried to use chatgpt to write an RPN script for the purpose, but probably because I'm not experienced with LLM prompts, I gave up after about a dozen non-working scripts.
EDIT: Just to clarify, I'm able to control them with button presses, but I dropped some money on the ProDeskSim F28 levers, which includes the fuel valve levers, so I'd prefer to find a way to bind them to axes. So I can set the LVar to 2/off with the button at the bottom of the axis, and I can set it to 1 when that button is released, but I have no elegant way to then set it to 0. Too bad the Bravo doesn't have detents you can set as buttons, like the Thurstmaster Airbus quadrant.