So, minor update in my experimentation process... @NotFastEnuf's firmware was set to the following:
#define MAX_RATE 860.0
#define MAX_RATEYAW 500.0
#define EXPO_XY 0.8
#define EXPO_YAW 0.6
I've compiled two firmware binaries, only adjusting rates and expo: 1) pitch and roll rate = 360; expo = 0 ("close to stock"), and 2) pitch and roll rate = 720; expo = 0.5
You can get them from my shared Gdrive folder: https://burtlo.info/e011-bins/
With these, you don't need the Keil dev environment, but can simply use the ST-LINK Utility for flashing your E011. They are the same as @NotFastEnuf's firmware (as of May 26 2017), with slower rates.