After too long a delay I had a go at trying these demos on a real 2600 (a Junior, and NTSC) by way of the Harmony Cart. What I saw wasn't always what Stella said it would be
The Cobra mk.3 and the Fer de Lance (or maybe the Gecko, I forget) had vertical grey bars appearing and vanishing in the "drawing area" of the screen. Only one, two or three at a time, and the exact pattern seemed dependent on the precise orientation of the ship. Oh, and the Cobra locked up if the orientation and zoom are set just so.
For the Coriolis station about half the vertices could not be drawn. Orient the station one way and it looked fine. Turn it around and it looked like the Thargoids hit it.
The Gecko (or Fer de Lance, I still can't recall) had no problems at all.
So, that's my bug report. Make of it what you will
Oh, that's perfect. I've read that each company to port Elite to another micro put some sort of system-specific variation into it. Finally adding the generation ships to Elite 2600 is so inviting that it would almost be rude to refuse the invitation.