Hi,
Well, when using the Segment > Mapping feature, it’s being applied in the “final stage”, once all segments are placed and transformed. It would be necessary to transform and map segments in the child generator, and then use the resulting geometry in the parent generator, but the RailClone plug-in doesn't work in that way – it just computes the mapping values according to the operators and applies mapping to the segments in the final stage.
An option might be using “nested RC objects” in your style instead of “nested Generators”.
I hope that clears it up.
Best regards,