Thanks! I will play around with it see if the GetRandomCellLocation function is sufficient, if not maybe you can expose a few more things to blueprint.
One more question - when I run the runtime sample project I get a compile error originating from Rules/PillarCornerSelector, because the ‘Model’ input on ‘Is Pillar On Corner’ is not connected. Connecting the ‘Model’ output of ‘Select Node’ to this seems to make the error go away, but I thought I would report it!