I noticed that some of my longer wheelbase locomotives were struggling at one end of the upper board..
Caused by the classic flexible track ‘dog leg’ effect where the curve is to tight..
So it was back out with my steamer to unballast the offending track..
As before I dealt with the problem by using a spare piece of peco set-track.
.. I also decided not to cut the track between the boards as it give a smother run for the locos.
I will probably ballast the track on the upper board (right side) but leave the left clear so I just unhook at the fishplates should I need to remove the upper board for any reason.