Can the MSM polar alignment wedge be adjusted beyond 60° to accommodate my latitude of 28° or lower?

Sorry, the tilting range of the wedge is from 0° to 60°, so it cannot be tilted beyond 60°.
In this case, I would recommend adjusting the tripod angle first so the wedge already starts at some elevation. Then you should be able to fine-tune the wedge to reach the desired angle.