I’m posting this here just in case there truly is a reason for the inconsistency, I have already filed a bug report for this issue here.
The differences are as follows:
Touchpad:
3 AND 4 fingers left gesture: move to left virtual desktop (if present)
3 AND 4 fingers right gesture: move to right virtual desktop (if present)
3 finger up gesture: move to above virtual desktop (if present)
3 finger down gesture: move to below virtual desktop (if present)
4 finger up gesture: show overview/cycle forward (default view, overview, grid view)
4 finger down gesture: show grid view/cycle backward (default view, overview, grid view)
Touchscreen:
3 finger left gesture: move to left virtual desktop (if present)
3 finger right gesture: move to right virtual desktop (if present)
3 finger up gesture: show overview/cycle forward (default view, overview, grid view)
3 finger down gesture: show grid view/cycle backward (default view, overview, grid view)
4 finger gestures: not implemented (!)
I definitely think this is an oversight, and not intended functionality.
Can anyone correct me on that, or provide more insight on why this might exist as it currently does?