We tried, they do not.
There is a tool- Foolclip- which works, but there are a few extra steps required to make it work.
R3D spans and the ProRes proxy are in the same RDC folder, and Cortex only (rightly) detects the RED media.
We have created an app that copies the proxy out, mirrors the red folder structure, and alerts the operator if there are spans. This is what we bring into Cortex. Spans only occur in clips longer than Bitrate x Time =< 3.9 GB, so it's not that frequent.
I believe this is due to the current reliance on fat 32 filesystem on the cards.
Not sure what method Cortex uses to detect RED spans, but if it is a similarity of the file name followed by a numerical three digit series, it might be helpful to apply that to ProRes files as well. At least have a preference "Detect ProRes sequential spans" in there somewhere, to enable or disable.