MeshCompare component in Volvox - "Key" input

Hello all!

I’m comparing a mesh in Rhino with a point could extracted from the 3D printed model, in order to analyze the displacement and the errors in the process (from digital to physical) and through time.
Now, I think the best way to do it was to use “MeshCompare” from Volvox plugin, which allows me to simply compare the mesh and the pointcloud giving me a distance as output.
There’s also a third input which is the “key” and it has to be a text. I guess, correct me if I’m mistaken, it’s the parameter that’s gonna define what distance I’m gonna get as output, but I really don’t know how to extract this key and how it should be set up.

Do you know how it’s gonna be related to the output?

I’m also attaching the gh script and 3 screenshots from the Rhino viewport. (01=the original points cloud, 02=the “clean” points clouds to be compared with the mesh. 03=the overlap between clean points cloud and the mesh).