It’s actually a little worse now. I found on ground that has the displacement mapping, the smaller tiles that have the (generated?) undulating and deeper polygons detailing — the profiles do not match up to neighbouring tiles precisely so you can see seams and varying gaps between all tiles as you get closer, and on more than one time I had each small tile in a radius suddenly drop down about 20cm when you get close to them, so you can see completely under the world.
The water still has those black joins too. One more for the list boyz!