You do need balance gauges to set up on yours - the TuneECU provision only works on the 1050 models
in UK (Belfast) does a really nice set if you end up buying some
Air volume is what controls the rpm - any additional air out-with the control system (i.e. the throttles themselves or the IACV valve) will have exactly the same effect as additional air through those devices themselves! - so that is why leaks through the IACV hoses will ALWAYS make it idle too high.
The idle speed is determined by two air paths - one through a very small opening angle of the throttles (they are not truly 'closed') and secondly through the IACV valve;
the former will be fixed and that is where the balance element comes in - each throttle 'closed' position needs to be set so each cylinder is receiving the same volume/mass of air (if they are not 'balanced' then each cylinder is attempting to run the crank at different speed and then the second part of the equation - the IACV (which operates on a closed loop system trying to set the idle speed to 1250 by adjusting the amount of air to each cylinder) gets confused as it is trying to react to each cylinder but is common manifold to all three!
Poor idle and stalling are most often associated with a poor balance condition on these bikes.
There is another setting that is used to help idle/off-idle condition called the idle fuel trim aka CO adjust - that enriches the fuel mass at idle/low rpm - but again, must realize that air is the PRIMARY mechanism for engine speed & even when lean, it should still be able to control the speed - so don't adjust that setting until you are confident you have fundamental idle control established and only then if you believe it is lean (that one should be only be adjusted by checking the CO content with exhaust analyzer)
And before you do any of that, ensure the TPS is adjusted/zero'd although again that will have more effect on fuel than air)