Thanks for the screenshots, this is the exact same thing I’ve been seeing since the USA World Update (indeed, I was not talking about trees and objects specifically but rather mentioned them as an example of the disfigured terrain).
The pyramid/sawtooth pattern became a lot more prominent since the UK World Update, and it’s less about the low amount of polygons, but more because of the poor shape retention of the terrain at lower levels of detail. The same amount of polygons could be used without changing the shape of the terrain that drastically, unfortunately it’s a weak aspect of the simulator at the moment.
I would highly recommend posting those screenshots over to the bug report about the terrain morphing (I’ll link to it again). It could certainly use some contributions like the great screenshots you provided!