Best practice for modifying external properties saved in SQL

We recently set up external property storage using SQL as referenced here for a client. One question that we were asking ourselves was what should the client do if they want to modify or add a property as it may not be the best idea to give them full access to the sql database with the properties. From what i can gather the property saved in the sql has precedence over the one saved inside the historian plus i don't think its the best idea to have two of the same properties for a tag with different values so I don't think doing the usual property import is a good idea. The best i could come up with was to create something custom that modifies the sql table directly but I wanted to know if anyone else has thought about this before or if there is a simpler solution to creating something custom or even something built into Canary for this.