I have attached a couple of examples of the symbols. The Degenerative faceting is unchecked and faceter mode is set to draft.
You have two ways (at least) to smooth out those facets:
1) Redraw the profiles, using Splines instead of arcs for the curves. See "Arcs vs Splines.jpg," attached herewith.
2) Use "Custom" Faceter Mode. See "Quality vs Custom.jpg." You may have to delete the extrusion and then Undo the deletion in order for the change in Faceter Mode to take effect -- or you might even have to delete the extrusion and then re-create it. When fiddling with "Custom," change only one of the variables and leave the other two at their default values.