Tempest 'Cut-Out Lever' not working correctly?

[56RAF_Roblex]

As far as I am aware,  the tempests 'Start/Cut-Out' lever could only be set in one of the three marked positions i.e. Start, Normal or Cut-Out.   In the game we can (and more importantly 'Have to')  adjust the lever manually one percent at a time through the range.  Can we have it working in three steps please in the same way as the Spit Vs radiator works in 5 steps?     It seems trivial but it is a nuisance trying to get an exact figure using a rotary control or hold down a key to put it up to 100% then another key to take it down to 50% where we might overshoot and have to change keys again and adjust it up a few percent again etc ?