Currently, if a specific custom field is added to a list/folder/space and then later determined that it is not needed there, there is no way to remove it without deleting it from ALL the areas where it may be also used. When deleting a custom field from a space/folder/list, we should not be managing the existence of that field, but simply removing it from the association with the specific area we are working with.

Right now, I simply have to leave the field in place and not use it, as if I delete it, I lose it on other areas where it is being actively used.