Weve just done a very complex area in Scotland with 260km of coastline in under 100,000 polys and 22 4096 x 4096 patterns.
That is normal to us, I’m afraid the output of sketchup is just a mess which may look ok and run in a fashion on on some systems but isn’t the standard of work we would want to supply to
any military or simulator user, and wouldn’t be accepted by them.
Martin