All cross rhythms are around the same difficulty to learn, except of course 2/3, which is the easiest. Once you get the hang of the 4/3 timing, learning the piece shouldn't be too difficult, since the entire piece consists of the same cross rhythms. It's the expression that then becomes difficult.
To best way to learn these cross rhythms is to learn each hand separately first. Then play hands together relatively quickly and continually adjust the speed of your right hand until the notes on the beat match up. Once you achieve this, your brain will understand the concept behind 4/3 timing and playing the cross rhythms should then become trivial.
After this, you should practice very slowly with a metronome to perfect your accuracy and sound produced. This is the secret to overcoming cross rhythms, at least it is for me