Save and restore multiple sets of personal logistics layouts
Mods introducing new content into the game.
Augmented or new ways of transporting materials - belts, inserters, pipes!
Are these layouts transferable between game sessions?
Nop, but I agree, this would be awesome.
Even MORE awesome would be if you could import/export text strings for the layouts. That would make sharing as easy as with blueprints. (hint, hint, hint.)