For AAO users, here is a RPN script for mixture axis that works for both standard and turbocharged models. The Axis variable (L:Bonanza-MixtureAll) has range of -16384 to 16384 (the AAO default) which is scaled in first step to 0 to 16384 range expected by MIXTURE1_SET. And scaled again to 0 to 100 range expected by BKSQ_MixtureLeverPosition_1
(L:Bonanza-MixtureAll)·16384·+·2·/·s0· (L:BKSQ_Turbocharged,·bool)· if{·l0·163.84·/·(>L:BKSQ_MixtureLeverPosition_1,·percent)·}· els{·l0·(>K:MIXTURE1_SET)·}
Reading the developers behavior xml, there is code that attempts to provide direct map to the correct mixture variable using standard sim events . If functional, this event mapping would allow the in-sim control mappings to work regardless of engine type. But in my tests this code under <Binding EventID="AXIS_MIXTURE#ENGINE_ID#_SET"> doesn’t work for for either engine type.
It might be valuable for developer to debug this. Because not every potential user is fluent with Spad.next or AAO.