Sorry numpty question alert

My friend has a gorgeous purebred Arab (Crabbet x Polish) gelding who's ridden in a barefoot saddle. He's always done endurance and loves to work. She doesn't have enough time to ride him so if I could get on with him we could have a fantastic time together.
I've tried him once or twice but just can't get on with the saddle. He loves it, but to me it feels like I'm sat on a cube with rounded edges. I can't get my legs round his sides properly and trot is just a disaster - I end up leaning forwards to compensate and suddenly we're in canter because he's so sensitive.
Is this what Heather's barefoot hipsaver is designed for??????
(As I said numpty alert....)