stuck with world composition

hi all,

i am trying out some of my wm landscapes in unreal and it works great.
single maps are easy and for the tiled maps i have followed the wiki worfklow of enabling the world composition-

and that is where i got stuck.
imported a 16 tile landscape and tweaked the scene some. i would like to proceed with the scene but:

  • i cannot move any of the tiles.
  • imported a single landscape actor into the scene and now it too cannot be moved.

apparently the tiles are locked. some refer to editing them in world browser but i cannot find the feature in 4.10 or 9.

also:
each time the project is opened all of the levels are unloaded which i have to do manually. can i preload the levels on start? is it an .ini thing?

attached are some screencaps:
basically i´d like to start expanding on the horizont with a couple of more instanced landscape actors, placed so they obscure the obvious cutoff.

presumably my issue has something to do with the way levels are handled, but i actually dont need them as such. if there is a workaround where i can import tiled maps into a single level, that would probably be best.