Idle VE table Load Axis

Add option for IAC % in the Idle VE load axis over ride.

Usage Example- Cable driven ITB running AN fueling. AN cannot compensate for the extra air provided by the IAC when load increases. If we allow fuel load to be measured by IAC %, we could tune idle more effectively?

Alternatively, should it be an adder for the main VE table?

No file or test is named. Start by locating the idle VE table, load-axis override, and IAC fuel/load handling, then determine whether IAC percentage should replace the load axis or act as an adder; done requires an agreed design and corresponding tests.

Written by the indexing model from the issue text.