Frogman, you are correct that the goal is to mechanically ground or couple the speakers to the floor.
The coupling discs will compromise the sonics but they should not negate them.
Unless, you plan on dragging the speakers across the floor, I would not worry about the 3 tiny dimples that the points would put into the floor.
The goal here is transfer the vibrations away from the speakers and into the sub-flooring system as expeditiously as possible. Anything between the point and the floor, including a coupling disc, will compromise that transfer to one degree or another.
-IMO
The coupling discs will compromise the sonics but they should not negate them.
Unless, you plan on dragging the speakers across the floor, I would not worry about the 3 tiny dimples that the points would put into the floor.
The goal here is transfer the vibrations away from the speakers and into the sub-flooring system as expeditiously as possible. Anything between the point and the floor, including a coupling disc, will compromise that transfer to one degree or another.
-IMO