Landscape and AirTurn unusable

Exported PDF files from Guitar Pro are always in portrait orientation.
But, its too small to read on the iPad Air in portrait position.

I can display my PDF files in SongBook with the iPad in landscape position. I see half of a page, text is bigger... its ok.
But when I use my Airturn Ped pedal, instead of showing me the second half of the page, SongBook switches to the next page... and its unusable. :-(

Could you try to improve this ? (making my airturn show the previous/next half of the page, and turn the page when necessary)

That would be so great !

Jruillier about SongBook Chordpro, v3.8.1