Oh, it only took me a week or so, TO FINISH a single background!!!
After experimenting for a while I get a good enough result that can be implemented. however, a direct export from SketchUp is not ideal because it cannot handle dpi. everything is exported at 96dpi while I must get at least 300 for the best result. Maybe I'll try manipulating it further in an image editing program but surprisingly clip studio does have a good tool when importing background images. to reduce moire I think I'll stick to 25 degrees for now, as 45 in default clip studio gets messed up easily.
Maybe I could do some in-depth process on how to do this next time if I had the time
