You can set the leakage amount mechanically with the wheel on top, and in the settings needed menu somewhere the amount of bellows movement change needed for controlling the reaction time of the notes played push/pull. Other wise you can ask Rees Wesson in the UK how he modded his Roland as he constructed a different air release valve internally. Mail me if you need his email. - Nout
There's nothing I HATE worse than valve holes too small for any accordion, especially Cajun (air valve or chord / bass).
I would be royally ****** if I bought a triple row that had the problem you've mentioned. I'm not surprised Roland is not in "the know" about a lot of things that have to do with accordions.
Technically, the air flow doesn't adjust; however, the tension of the bellows is completely adjustable. If you loosen the tension a little, it makes the air flow much more effective.
As for the sound setting, it is a matter of preference, but I much prefer the "Cajun" setting and the "Alpine" setting. To me, if you add the hammond sound, it gets too wavering.