I just wanted to thank everyone for documenting so much on this issue. I just came into possession of a PAL Intellivision with the ZOE RGB board installed. I was pretty bummed to realize it would not work with the OSSC. It shows up on my PVM fine, but totally ignored by my OSSC with the same message as others.
I doubt anyone has a solution as it would have been mentioned. However, I was curious if this is something someone is looking at, might be addressed with the Pro version of the OSSC, or what I might do to assist or resolve this issue (if there’s any hope at all).