BP function node inputs can unintentionally add or clobber metadata

Blueprint inputs are added to nodes as metadata, with the key set to the pin name and the value set to the default for that pin. Since blueprint functions allow you to name your own input pins, this allows you to (intentionally or otherwise) inject metadata into the node. Some metadata tags such as DisplayName share names with common variable names, which can cause unexpected results as reported in [Link Removed].

A potential solution would be to append a string such as "_input" to the end of input pin metadata keys. 

1. Create a blueprint function
2. Add an input variable. Change the name to an existing metadata tag (such as DisplayName)
3. Modify the default value. Observe that the node now behaves as if it has a metadata pair matching your input's name and default.