I just updated to build 4142 and guess what? - progress doesn't work properly anymore. Thanks Roku. grr My Roku still on build 4084 works just fine. As I suspected, they're no longer firing the "isFullResult" message so the last playback position received (which should be within 10 seconds of the end of the video) is getting saved as the progress.
Roku announced they wouldn't be adding new features to deprecated components, but I suppose that doesn't preclude them from breaking them. I'm not even going to bother reporting this since I know I'll get no response. IF I can still update the channel (which I'm not sure whether or not private channels with deprecated components can still be updated), I'll try to fix it. I may not get to it for a while since right now I have to take care of the giant shafting I just got from Roku.
Someday I'll recreate this using the new Scene Graph crap, but that's going to be a while off (see above note about giant shafting). You could edit the resume.xml file to get the "Watched" to appear, but I don't recommend that.