SubD component crease options inputs

I’m working on a project with a lot of vacuum formed parts.

I made a little script that takes SubDs, finds their minimal bounding boxes, and gives me the option to split the subDs in half along any axis of the bounding box. (red = input subD, green = output split subDs)

The crease and corner crease inputs on the SubD from Mesh component are giving me unreliable results.

-What makes this component decide if a vertex is a corner or not?

-Also, is there a reason it doesn’t accept boolean inputs?

-Also, important: Is there a mesh component, native or plug in, that can crease mesh vertices so I can feed the SubDfromMesh component a pre-creased mesh? Or maybe a way of tagging mesh vertices as "corners? If I could do that, I could maybe only crease the vertices that intersect the splitting plane?

Here’s the definition. Thanks to @Helvetosaur for the minimal bounding box component.
Minimal Bounding Box (41.4 KB)

Here’s a C#-script for creasing meshes: