How difficult would it be to subclass Spline and add some RailClone-specific variables? I love using Material ID to toggle segments, but it would be amazing to have additional properties to mix and match segment combinations. For example, I have two generators: one for wall types (1,2,3), and one for window types (A,B,C). For these possible combinations (1A, 1B, 1C, 2A, 2B, 2C, 3A, 3B, 3C), I must use Material IDs 1 through 9... which gets a bit messy. But, if I could pair Material ID with some other generic integer variable, say "Window ID", I can mix and match with ease. Thoughts?