I discovered an annoying bug in TSRE5 when laying certain kind of shape with inclination, the best example is A1tDblSlip6_3d. Sectionidx with vector offset (z) different than null counted incorrectly in tdb as shape inclination would be zero:

TrackShape ( 22021
FileName ( A1tDblSlip6_3d.s )
NumPaths ( 6 )
ClearanceDist ( 35 )
SectionIdx ( 1 0 0 0 0 28868 )
SectionIdx ( 1 0 0 12.471 0 28869 )
SectionIdx ( 1 0 0 25.529 0 28868 )
SectionIdx ( 1 1.6512 0 0.0912 -6.32 28868 )
SectionIdx ( 1 0.2784 0 12.4864 -6.32 28869 )
SectionIdx ( 1 -1.159 0 25.4649 -6.32 28868 )
CrossoverShape ( )
XoverPts ( 1
XoverPt ( 0 0 15 )
)
)
Red lines are counted wrong in tdb, as if TSRE wouldn't calculate vector elevation based on inclination. Placing the same object with zero gradient looks fine.