I've seen Pasos that could canter without issue. I've seen others that struggled badly.
Paso Finos are relatively small of stature. While that does not make them a "bad" horse it does mean that they are likely to lack the bone and other structure necessary to carry a modern American (male or female) over fences as a matter of course.
While any one might do quite well as a breed it's not what they were bred to do.
So if it were me I'd not do it. I see significant risk and a minimal gain. As with all things, YMMV.