Removing Shared members from journals member selector

Summary

Is there any way other than valid intersections to hide [ideally]/remove ability to post to shared members when selecting members for a journal?

Content

Valid intersections are clunky/the error message provided not particularly intuitive. I can't see a case for ever posting to a shared member, is there a way to remove shared members from search? I appreciate you could use the distinct member name search to give a specific parent/child combination but only users who use the system a lot/have built the hierarchies will really grasp this. 

Apart from being clunky/not very intuitive postings to shared members is currently making it near impossible for us to remove a now defunct shared entity hierarchy.