For 10-11 I backtracked out of 10 (using an unmapped trail I found on the way in) and went north of the big marsh, mostly to avoid having to go through giant rhododendron south of the marsh. UsynligO played a tune as I passed near 14 - it is a different tune than the one you get at the control you’re headed for (I had this happen before on a course at Tyler SP, so knew what was going on). I proceeded to 11, which was one of those “the tune is playing so I must be here” locations. Then on the way to 12 I hit the unmapped trail, mistook it for the mapped trail and explored it for a bit (the trail runs north from control 10, turns NE and passes between 13 and 14, and hits the mapped trail at the bend SE of 12).
I wondered if maybe it played a different sound and I was just too tired to notice. It seems like a reasonable thing for it to do. Will have to pay better attention next time!
I considered doing what you did 10-11, but thought I'd give it a try going straight just to see if I could. I never got trapped by rhododendron but I clearly lost track of where I was.
Having seen the trail on the way to 10 when I hit it on the way to 12 I figured that it was part of the same trail. I hoped it connected to main trail so I turned right (east) on it and sure enough it did.