So the water injection switch you push in and slide. But this means its always on. Not sure hoe sims will handle that but will cross that bridge when I get there.
Originality is the thing I'm after. The controls are an after thought really. Will do what works best in IL2 when i look in to it.
Games - specially IL-2 Bo'X' that use momentary press for all commands (exception Flaps and Landing Gear) - suposedly for be friendly for "casual new gamers", since this game series start as a "combat flight game", not "combat flight simulator" , but a switch always ON don't cause issue, don't send repeatedly commands.
But are another issue in this game, the game expect that you press a key/button or turn a switch for turn Water Injection ON and again for turn Water Injection OFF, awkward with a ON-OFF, switch resulting in unrealistic operation (Turn ON for start, turn ON again for stop).
So for deal with this limitation (again due the game simple commands approach for "new players) need use a keymapper software, e.g. Joystick Gremlin that will send a momentary command
when switch is turned OF and another momentary command when the switch is turned OFF, mimic real life switch.
An option use a optocoupler circuit between switch and controller for send only the momentary command, drawback is that optocoupler require external 5V source.
Other option is use an Arduino with Lynx CUBE firmware as USB controller for you throttle quadrant.
This firmware deal with this games issue, a ON-OFF switch will only send a momentary command in the change state for OF and OFF positions.http://lynx.dk/cub-firmware/
Arduino PRO Micro +MMjoy2 firmware (by MegaMozg, VirPil electronics developer) is other option.
The popular USB Controller L.Bondar BU0836A will require the use of keymapper sofware, since don't deal with OFF state of toggle switches.