I've been trying to speed up the way that DSL Tools lays out a bunch of lines and shapes when you start with a model file and no diagram.
By default the shape layout takes a long time to layout the shapes in a rectangular grid, and doesn’t leave enough space for the lines to route efficiently. There is a straightforward workaround for this, which is to do your own shape layout, leaving enough space for the lines. This can speed it up by 1-2 orders of magnitude. This is what I did:
To do the overrides you have to set IsDoubleDerived to true, which causes the Generation Gap pattern to be generated.