HOW DO YOU ADD VERTEX TO AN EXTRUDED SHAPE IN PROSTRUCTURES? The extruded shape has been made using Modeling->place shape->solid by profile->solid by extrusion.
Can you post a sample file? If you are using parametric modeling you should be able to enable the base profile and edit it using the add vertex tool see:
https://communities.bentley.com/products/microstation/f/microstation-forum/184484/connect-can-you-modify-a-profile-that-is-used-to-define-a-parametric-solid-how