RE: H9 Cub differential ailes
G'day Mate,
You could use differential ailerons, just program in some differential, in the TX, easy.
And/or you could program an amount of rudder/aileron mix, I'm sure the TX would allow that.
Be aware the plane will still fly, without any differential or Aileron/ rudder mix.
It just flys better, with them, all you may need to do, is use some rudder, in the same direction as the turn, ie, left turn, left aileron & some left rudder, & so on.
It's not such a big deal, so don't panic, it'll be fine.