Hi!
This is an interesting facade. I've had a go at solving it using RailClone as it seems better suited to this task. In the attached file there is a version which uses a single spline to define the overall area, this will give you the clipping around the edges that Forest Pack will not do. There's also a more complex version that adds the frame around the outside and uses a spline as a path, though this is a bit of a WIP at the moment.
(http://i.imgur.com/UMvF4Rd.png)
Version 1
(http://i.imgur.com/jNsYbQf.png)
Version 2
Please take a look. I'll continue to work on this and update here if I have a more refined version. I'd like to add the 60 degree rotations you mention, at the moment I'm cheating with some mirror operators ;)
I hope that helps,
Best wishes,
Paul