Omit variations of gap fillers
One of the most valuable features of RailModeler (in my opinion) is the gap filler. However, when it finds a solution, all the permutations of the tracks are also listed. I am only interested in seeing a single, unique line for each solution, since I can easily permute the tracks manually, should I have the desire.
The implementation requires only a few lines of code. (For each preliminary solution, form a set of the tracks. Keep only solutions, whose track sets are different. Sort the tracks according to their respective length.)
If others like the feature as it is now, I argue in favour of an option in the preferences.