MOT_PWM_TYPE = 3 (BrushedWithRelay) doesn't work with FRAME_TYPE=2 (OmniX)

Hi,
My rover config is OmniX with mecanum wheels. I use brushed motor drivers that are controlled by PWM and a relay for reverse.
For relays I use Aux OUT (3-6)
RELAY_PIN=54
RELAY_PIN2=55
RELAY_PIN3=52
RELAY_PIN4=53
The relay setting works as expected - all four relay outputs behavior is predictable
The servo mixing seems also OK with settings:
SERVO1_FUNCTION=33
SERVO2_FUNCTION=34
SERVO3_FUNCTION=35
SERVO4_FUNCTION=36
But it doesn’t matter if I choose MOT_PWM_TYPE = 3 or not - the main port servo outputs are of servo type (pulse is in 1-2us range instead of duty-cycle based PWM of 16kHz)
What is wrong with the settings or I’ve missed something?