Watching the reverse POV's, my hypothesis is that the higher tolerances in the wheel carrier assembles cause oscillations that are far more noticeable on B&M wing coasters due to the train's heavy-off center seating arrangement. Coaster wheels have a natural arc to them so they can conform to the rail and navigate forces. The tolerances being different from what we are used to cause the wheel carriers and assemblies themselves to "wrestle" on an axial plane ever so slightly over the top of the rail, inducing a bump/bounce that is exacerbated by the wing design.
You can simulate this by placing your palm flat on a pool ball that is resting on a somewhat smooth surface while applying very high pressure, fingers outstretched widely flat, and trying to ensure the ball doesn't move *at all* under your flat palm and stays centered. The ball and your palm will try to counterbalance each other, but BOTH your palm and the ball move ever so slightly nonetheless since there is no tight forces on the sides of the ball, just the top where your palm is, and the surface on the bottom of the ball. The downward pressure exerted by your body (palm) will always cause some kind of micro-movement, no matter how hard one tries to keep it perfectly still. The tolerances in B&M's of late seem to permit more "palm to ball" movement than in years past.
Apply similar physics onto a rollercoaster wheel assembly moving through inversions and all kinds of directional changes - and there you have it. A lateral or vertical bounce depending on where you sit that becomes more or less noticeable.
It's not "fixable" per-se without a train tear down, but the GP will eat it up nonetheless. No real issue, unless you're like me...LOL