That looks really cool! So from what I understand you're building a mesh from the uvs to make that plane geometry, getting the closest location from it using the locator, then finally sampling the location's position but with the original sphere to get the red point's position?
Yes, that's exactly what it is doing.
I guess the thing I'm struggling with is even if I built that mesh from uvs I won't have that locator on my setup so I would have nothing to query from.
This is using a locator in this case, with it could be anything, like another mesh's point position... If you don't plug anything in the position port you won't query anything either.
I kind of figured I would have to extract more info from my initial closest location when I get the uv value so I can use it later to map onto its updated 3d position. Which leads me to another question: how can you sample any other info from a location? For the life of me I can only pull position out of it, but from what I understand in this link there's way more properties that I should be able to pull. I'm not too sure what the names of the properties are and how to check though as the watchpoint is empty.
You can query almost any property from a mesh, relying on either the point_component or the face_component. You just got to make sure the "default" type you are setting on the "sample_property" match the actual property you want to query. If you can't see the data on your watchpoint, you can use a "dump_object" node to write your object to a text file. there you can see every single property it is holding, along with its data.