Unfortunately, ignoring the phone call isn't a guarantee either. The only surefire solution found, at this point, is to actually uninstall ITF.
It does appear that opportunies related to rabbit-holes are working, but so far, I've had them not fire when I:
Ignore the call
Take the call
Am on a community lot and ignore the call
Am on a community lot and take the call
Go from the home lot to a community lot and ignore the call
Go from the home lot to a community lot and take the call
However, I've had them definitively fire for the Laser Rhythm-a-con skill...