I had the same problem as listed above; when loading Monkey, the dialog showed that the drivers, firmware, and usb were not updated and my POD HD 300 would not connect. I ran the terminal csrutil routine, rebooted my macbookpro, open Monkey 1.71 and everything showed installed with the green check mark. I then open HD Edit and it loaded right up. I, too, am running El Capitan Beta--because I am a tester for Apple.
The "hack" works perfectly. Just don't forget to turn csrutil back on {enable] unless you want to leave your system vulnerable.