Just out of curiosity I had a look.
Cinerender does not show the hard edge of any elements at all (not even walls & slabs).
So a morph surface will show but not the edges, and a morph line will not show at all.
So unless there is a setting I am missing in Cinerender options, it look as though you will have to combine a sketch render (where the lines will show) with a Cinerender.
One of the forum moderators.
Versions 6.5 to 25
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
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