Pass None to UDT parameter

I am using system.tag.configure for creating a new instance of a UDT. The UDT takes parameters that are all Strings. Some instances have None for some of the paramters, but when the tag is created it shows the string null instead of actually being null. How do I pass None correctly as a parameter to the UDT?

I believe i just solved my own problem. Just do not send the parameter in the dictionary. But this does leave the scenario where you are updating an existing UDT instance, how would you use system.tag.configure to change a tag in the UDT to None?