I mean the above works but only in the sense that on the airport no buildings are sinking into anything else. The surroundings of the airport are quite ugly with plenty of floating buildings and some sunken ones, too.
I'm glad I waited to get the Seattle airports until I had enough rewards points to get it for "free" because otherwise I'd be mighty upset about this. As it is I'm most likely going to uninstall the airport scenery and go back to XP default. If you're reading this post in the future from a Google search, I recommend you don't buy the DD product.
It's really a shame that with both TE Washington and DD Seattle Airports having been out for years now that whichever side needs to fix something to make it compatible hasn't done so yet given the cost of both products.