Looks like the NNA_TIfcCurtainWall record just carrys id info, nothing to do with Glazing.
I did find what I was looking for using the worksheet functions:
I had no idea these existed!?
Can these be retrieved in a script?
Strange I'm not sure how to see this Wall Record you are mentioning.
I did pull up a list of hidden records and see a NNA_TIfcCurtainWall record. Will dig deeper.
I don't have a file showing glazing area, and running a criteria with all, and checking object types of every retrieved object, returns nothing.
Will keep investigating.
I would take the Function Node and use the formula x[:-2] (to remove the last to items of the string, or x[:-1] to remove the last one etc.). There will be other possibilities with other nodes but I first had to search the right ones.