Dear @igor.sokolov, thanks for your remarks below (and apologies for the late reaction).
Context: These are known issues. In the context of the IFC Rail Implmenters Forum (IFC Rail-IF), we are just about to start testing the linear placement topic. Our stakeholders provided some dataset, and we (Technical Service) are building some reference IFC files, for implmenters to test both I/O. During this topic’s testing, we definitely consider adjustments to the documentation.
Proposal: I guess your help would be very much appreciated. If you are interested to join, just send me a PM. I’ll get back to you right away with all the info to get on board (next IFC Rail-IF meeting is 24th Sep 3pm CEST).