The only thing he can mean is the x/y positions.
And dont change it.
Landscapes should never be moved.
If you ended up with non-integer x/y loc on the landacape you did something wrong somewhere else or worse, you moved the landacape already.
That nonsense aside:
Generally, if you enable displacement you get seams.
The landacape (or sorry excuse thereof) is not meant to have a resolution greater than 1 vertex per meter.
In non game environments (movie, a render etc), the way to get it going with more resolution is definite not tessellation and RTVs.
Simply reduce the lansacape scale to 50 - for 1 vertex every .5m, or less of a scale even.
This comes at an obviously insane cost of perfomance, so know ahead of time your viewport or Pie are going to run around 2fps.
In game environments, remove that trash system and idea.
Make meshes in a DCC and use them wherever you see fit - between 2 landscapes as well - without ever having any issue.