Looks like BFC coloring is fooled by noclip statements. See:
https://www.ldraw.org/cgi-bin/ptdetail.c...231p01.dat
https://www.ldraw.org/cgi-bin/ptdetail.c...69bpz4.dat
https://www.ldraw.org/cgi-bin/ptdetail.c...086ps1.dat
These files show 3 different types of wrong rendering.
Also: I have had problems with zooming level (goes to extreme zoom in) when rapidly switching between rendering modes and rotate view. So far I've not been able to reproduce this reliably.
https://www.ldraw.org/cgi-bin/ptdetail.c...231p01.dat
https://www.ldraw.org/cgi-bin/ptdetail.c...69bpz4.dat
https://www.ldraw.org/cgi-bin/ptdetail.c...086ps1.dat
These files show 3 different types of wrong rendering.
Also: I have had problems with zooming level (goes to extreme zoom in) when rapidly switching between rendering modes and rotate view. So far I've not been able to reproduce this reliably.