Yes agree, I haven’t compared the 2 levels yet. Somehting I found in the source of the LE firmware shows that they are defining “Fast PWM” for certain machines like the Mini V2. I’m wondering if that got defined in the DO versions.
Here is the code snip from the v2 LE firmware where that gets setup:
//=============================================================================
//=============================== Extra Features ==============================
//=============================================================================
// @section extras
// Set number of user-controlled fans. Disable to use all board-defined fans.
// :[1,2,3,4,5,6,7,8]
//#define NUM_M106_FANS 1
// Increase the FAN PWM frequency. Removes the PWM noise but increases heating in the FET/Arduino
#if ANY(MiniV2, TAZ6, Workhorse, Sidekick_289, Sidekick_747)
#define FAST_PWM_FAN
#endif
// Use software PWM to drive the fan, as for the heaters. This uses a very low frequency
// which is not as annoying as with the hardware PWM. On the other hand, if this frequency
// is too low, you should also increment SOFT_PWM_SCALE.
#if ANY(TAZPro, TAZProXT)
#define FAN_SOFT_PWM
#endif
// Incrementing this by 1 will double the software PWM frequency,
// affecting heaters, and the fan if FAN_SOFT_PWM is enabled.
// However, control resolution will be halved for each increment;
// at zero value, there are 128 effective control positions.
// :[0,1,2,3,4,5,6,7]
#define SOFT_PWM_SCALE 4