tl;dr: when using the Bravo with default MSFS controller settings, HDG bug in the Turbo Arrows moves a minimum of 2 degrees, and does not accelerate (works in other aircraft), mouse achieves 1 degree precision. Unable to locate the (local) variable(s) that control(s) HDG/CRS via Dev mode and SpadNext event/data monitors, can't solve problem with SpadNext profiles.