I've had the same issue while testing a book-style project on mobile. I don't believe there's any easy way to separate mobile swipe events from other kinds of left and right navigation.
For now my solution is to have a checkbox on the first page of the project that reverses the direction of navigation. Hopefully people will use it. :)
This is what I have in the deck script currently:
on navigate x do if innercover.widgets.mobileswipe.value if x~"right" go["Prev"] end if x~"left" go["Next"] end else if x~"right" go["Next"] end if x~"left" go["Prev"] end end end
(Thank you to Internet Janitor for answering my questions about this in the past)