Bil, off the top of my head, here are the big violators. I have all my test results on my laptop that is not with me today.
1. Recent high end Lionel aluminum cars.
2. Atlas passenger cars.
3. Weaver passenger cars.
4. Atlas caboose--The worst.
5. MTH Rotary snow plow.
6. GGD passenger cars.--Scott Mann was the first to resolve the problem.
7. Third Rail RDC.
8. Smoking caboose from Lionel, K-Line and MTH.
This testing was done with rolling stock. Every car listed above with a choke would restore a 10 signal.
All the above would bring DCS signal from a 10 to 3-4. In testing the rev L TIU, Jason let me keep it a bit longer and all the above trains came up with 10 signal with no choke or light bulbs on the TIU output.
MTH and K-Line passenger cars did not cause any problem as the lighting was powered directly from track voltage.
When we see the next version of DCS, this will all be ancient history. When the choke fix was first used, Scott Mann contacted me as he felt it was very important for him to change his lighting boards as the 3 rail DCS guys were buying his products. He did so and has a great LED lighting board in all his passenger cars now. Very DCS friendly with any TIU.