It's frustrating you can't find the click. As I mentioned above I've had it three times and managed to narrow it down by systematically going from pedal to crank to chain ring bolts, bent teeth, to EBB to BB. I've pedalled one legged (when no one was looking) to try and isolate to left or right. At each stage everything was cleaned, swarf removed and greased. In my cases once was a pedal, once was a crank arm and once was the EBB moving under load and creating a groove. If you remove the EBB check to see if any of the holes have coalesced, file down any swarf and clean the shell. I don't use a torque gauge but the EBB bolts need to be ' really quite tight' ie enough to make big dints in the alu without squashing the BB cartridge.
Above you ask about gaps and shims. I recall that my old raven frame had quite a visible gap between frame and EBB even when the bolts were tight which I filled with grease and never had a problem. The RST frame seems tighter. Good luck!
