It has not been addressed in Idyllshire or Ishgard; still only one bell those places.
It has been addressed is all the other cities with addition of multiple MB and nearby summoning bells.

How tall would you make it? There are still going to be trolls which will get on their biggest mount and sit on top of the summoning bell. If you set the icon higher than that a Lala will have to swing the camera in a crazy upwards direction just to target the bell. Then some bell icons in some cities would be in the ceiling; not an ideal situation.