Wish I'd read your pre-report a little earlier. I was just up there today, figuring Rainbow View as being the turnaround point. (I'd hiked OBOFR a few years back, but turned around after getting tired of climbing over several large rockfalls, and not knowing how many were ahead.
This time I already knew about the scrambling, so figured I'd go back and finish it to Rainbow (I have a book, Trails and Tales of the Sierra, which makes no mention of anything other than going over a "few" (extremely under-exaggerated) rockfalls. I got pretty close, according to the GPS (1/2 mile at most) thinking there CAN'T be many more big rockfalls, and ran smack into a heavily-forested blockade, which I half-heartedly scrambled around trying to see past, but could find no trace of any road or trail beyond.
3-early twenties hikers ahead of me had turned back there, and being an older solo hiker that was hot and tired, I didn't feel so bad about turning around there. I just couldn't see pushing it, as I was exhausted from scrambling the numerous rockfalls. (it was hard enough finding my way back across some of them to where the road was, and not ending up too high or low with no clue of which way the road was).
Switchbacks? Never heard of 'em, but I guess that makes me feel better, because according to the book you just walk there, scrambling over a few rockfalls on the way. Nothing about an overgrown jungle blocking the trail with no (obvious) paths through or around. When you do your report, be sure to include where and how they're found.
Gary
Yosemite Photo Galleries: http://www.pbase.com/roberthouse/yo