Two-finger scrolling on jsui

Two-finger scrolling on a jsui object doesn't seem to work. If a regular Max object extends beyond the boundaries of the patcher window it's possible to use two-finger scrolling on the object to scroll to the bottom of the window. This doesn't work if the object is a jsui object.

FWICT, it seems that two-finger events are intercepted by jsui, but without allowing me to query them; at least, I'm not aware of a function that would allow me to do this.
Am I missing something?