@Ocpop
As the others have said, I wouldn't treat Joplin as a bailout... And I wouldn't personally go down it if I were in bonk mode. There are too many spots where it requires 110% focus and 20% luck. Ask the Professor who is still nursing an elbow that looks like the Eye of Sauron.
@mike recently said that 90% of riders will walk some of Joplin. I think he lowballed it...
Also... If you start at Maple Springs, bailing out on Joplin puts you on the wrong side of the mountain. You'll have the climb out of Old Camp
, and then you'll have decision time on STT. If you go down the Luge, you have the whole run from Cooks to Silverado on Santiago Canyon Road. I've done it quite a few times and it's scary. If you ride STT out to the end (only 300 feet of climbing from Luge back to Modjeska Grade), and hang a right on Modjeska Grade, you can cut some off, and enter Santiago Canyon on the slightly downhill, mostly flattish section of Santiago Canyon Road.
However you get back to Silverado, you will have the slog up Silverado Canyon, which is approximately 5+ miles and 1000 feet from the tree farm. Not a great way to end a ride (Done that...
).
If you're bonking at the peak, the easiest way back down is to go down Maple- just watch for the knuckleheads in the 4x4s. Hopefully, with the rain, the gate will be closed. One can dream... Even though it's a fire road, there are several launchable water bars... Make the most of what'cha got.
The second easiest way back down is actually to head across Main Divide to Motorway. That is only 6 miles and 1200 feet from Four Corners. Most of the climbs are short, and it trends downhill. The long one at Bedford can be walked in under 10 minutes.
Edit: I left descending Harding off the list, because the dozers have been "fixing" it for the last couple of weeks. A Harding descent makes the return pretty easy, but you will still have the slog up Silverado at the end.