I did the same thing with my e-fliight powered passport. Chris Moon advised me to limit the top end using the thottle curve rather than ATV (for the same reason that Ryan mentioned, it will reset the top end recalibrating automatically to the stick full position).

Just go to Thro Curv; roll the scroll bar over to point H- max and reduce from there. You can adjust the other points down to get a linear feel on the ground (do it by ear on the ground statically for starting purposes).

I adjusted my thottle curve down on the Passport to make the noise requirement in FAI. The Chip prop was over the noise limit on static (like 96 db over grass). I dialed it down to like 70 percent on the throttle curve H point to get it to 92 db over grass. It has very similar feel to the 170 DZ dialed down at 92 db on the VF3.