At the time of writing, Raspian is running Linux kernel 4.1.19 that has a bug in the bluetooth driver for Sony DualShock 4 controllers with newer firmware. Kernels as of 4.5rc1 have the fix. Until Raspian kernel packages catch up the solutions I can see are to backport this fix by patching and compiling a custom 4.1.x kernel or just running a DS4 of an older firmware.
So one of the Hobbywing ESCs is defective and will need replacing. It only runs for a few seconds then dies. The fact that only the defective one has a distinct high pitch whine when powerd was a clue.The other issue is that the reverse mode is less power and thus spins slower per pulse. Maybe this can be compensated for in software, but I'm not sure the rate is proportional. Would be a bummer to have scrap these and go with more expensive ones.