In my environment I use some Custom Property fields to control who can see certain nodes, whether a node is part of my Development, Demo or Production environment, if a node is considered Vital to the environment or Non-Vital, etc. I read posts by others who use Custom Properties for similar purposes. While I have these in-the-background Custom Properties, I also have Custom Properties that I want my user community to be able to see.
Adding the ability to hide certain Custom Property fields from webpage displays would help keep only the ones you want in the public eye visible.
To take this a step further... Soon we will have our customer's logging into the website. While I realize that I can setup their Views differently than I set up my support staff's Views, there will be Custom Property fields that are for internal use only and should not be visible to customer's. Instead of having a toggle for hidden/non-hidden on each Custom Property field, if we could have more control over Account Type values and then list Account Types that could view each Custom Property field, this would essentially act to group the visibility.