I’m always amazed about what I pickup when I keep up with this forum, so thank you. A quick look at configuration_adv.h yields this define:
#define CHOPPER_TIMING CHOPPER_DEFAULT_12V
And here are the other possible values for CHOPPER_TIMING from tmc_util.h:
#define CHOPPER_DEFAULT_12V { 3, -1, 1 }
#define CHOPPER_DEFAULT_19V { 4, 1, 1 }
#define CHOPPER_DEFAULT_24V { 4, 2, 1 }
#define CHOPPER_DEFAULT_36V { 5, 2, 4 }
#define CHOPPER_PRUSAMK3_24V { 3, -2, 6 }
#define CHOPPER_MARLIN_119 { 5, 2, 3 }
#define CHOPPER_09STEP_24V { 3, -1, 5 }