I think it was released only within the past day or so, and I agree not a millisecond too soon.
As to whether it re-renders to stitch the segments together, I think not. At least in my limited testing, i could find no visible difference between the RG output and a direct AE output using ProResHQ and 4444. I mean NO difference, even blown up 200%.
The post-render action that results in a .mov or h264 file (your choice) does seem to be a re-render. I did notice some chroma shift using ProResHQ as the post-render option. Reds particularly were not drastically but noticeably different in saturation and hue. Maybe a function of ffmpeg? Anyway the post-render option is redundant for me - i pull the final render into Premiere for final tweaks and output to master.