Do laser-cut or 3-D printed parts that come in a kit have to be described in the flight log as in para 4.c.i, ii, and iii?

No, laser cut or 3-D printed kit parts do not have to be described per rule 4.c. The rule addresses student/team created parts and materials using digital manufacturing processes themselves. That would mean teams building from 3rd party kits do not need to describe how the parts in those kits were created. The type of kit(s) would be included with any other materials under 4.a.i. "Materials used to construct the plane."