I have two notes regarding flooring:
1. Number of materials should go from 1 to 20, and not from 0 to 20. If set to 0,- RC object is not rendered,- maybe that's intentional,- but not intuitive.
2. Parquet Fern Chevron
has middle plank without correct UVW.
I managed to fix this by extracting "Box31" element and applying uvw with settings: 74.75cm x 10.5cm (not sure if that's correct):