The Mk3 doesn't seem to read/calculate the EDID info 100% correctly, and I guess it could be the TVs giving out the wrong information. When the Mk3 checks the EDID info it adds only 3 modes to the list, but I think the TVs are capable of a lot more because I've seen them do it when connected to PCs, Raspberry Pis and game consoles. It looks (at least to my not-expert eyes) like the Mk3 is getting most of the information correct for the resolutions it lists, but not the back porch setting, and then because of that, the frequencies are wrong which results in no picture. Below is what the Indivision tool returns, I've highlighted the fields I think are incorrect.
You are correct, I can confirm a bug in the EDID mode evaluation. Thank you for your clear and useful presentation.
It is also correct in that there are more modes that could be added from evaluating more EDID info from some devices where some of the more interesting "TV modes" are located. First we need to get this bug corrected per an update to the config tool.