We've put a few inertia reels in and they are always a disappointment.
The geometry of the cabin doesn't allow for the size and type you need. You end up with this giant black 'box' thing behind the pilot's head floating in space, practically. It barely gives the travel he needs while giving the rear passenger something to hit his head on when getting in or out.
In acrobatics, they don't help much. A jerk is required to get them to lock. Although the lap belt does most of the work in acro.
So, yeah, its possible. I rate them as a 'meh'.