Here are some more fixes and updates for the layout editor.
You should find the O key seems similar to how it worked in the old version. In reality it's not the same at all. Because in the old version, you had BOTH the objects 'in hand' selected and the world objects were still selected at the same time, which caused various problems and limitations that users would learn to work around.
In today's version, after pressing O, only the objects 'in hand' are selected. If you want the newly placed world objects to be selected, as in yesterday's version, use PASTE which is CTRL+V.
You can also switch between the 'in hand' and 'world objects' selection styles by using COPY (CTRL+C).
So...
World objects selected, press COPY -> objects now selected in hand
Clipboard objects selected, press COPY -> it's really UN-COPY - reselects the world objects
Changes from 0.6R13 to 0.6R14 :
Layout editor :
Place objects (O) key is now equivalent to PASTE then COPY
COPY key is now reversible so you can reselect the copied objects
FIX : Sometimes marshall type could not be selected before placing
FIX : Real world objects could still be selected after a full clear
https://www.lfs.net/forum/thread/92067