I'm looking at putting an include (10cm down on one track and 10cm up on the other) to create two levels (one for fiddle yard and one for goods yard).
Trixbrix do include pillars which are in 3.2mm (1 plate) inclines so that seems to be the accepted norm.
https://www.trixbrix.eu/en_US/c/Supports-Pillars/30