@Forenkazan - applying the correction to the feedback path is the wrong approach (in my professional opinion. )
Corrections for wheel slippage should be applied to the command input, NOT the feedback.
As @PJohnson pointed out, the feedback is used for commutation of the motor, so you cannot apply any “correction” that would cause misalignment of the stator’s electromagnetic field with respect to the rotor’s permanent magnets. The drive’s commutation algorithm needs to ensure they are always aligned, or the motor simply will not work.
When you said slippage, we thought you were talking about slippage of the encoder on the motor shaft, not wheel slippage.
As I say: apply any corrections you like to the command signal, but don’t touch the feedback, please.