hello mate, you probably missing a step.
If you remove de angle of any group/component in SU you need to refresh Octane Viewport, because new geometry settings are saved. Another thing, groups inside groups can have different soften value, so we need to select that part(group) and correct the soften value.
I don't soften geometry in SU, i use the smooth option in Octane.
Check here how i did it.