LMX2820: Disabling the State Machine Clock on LMX2820

Tool/software:

Hello,
I have a question regarding the state machine clock of the LMX2820.

During our previous work with the LMX2594, we observed a significant improvement in spurs at ±fosc offset from the carrier after disabling the state machine clock. This leads me to the following questions for the LMX2820:

(1) Is it possible to disable the state machine clock on the LMX2820? If so, which register bit(s) need to be configured to achieve this?

(2) If disabled, can we expect a similar improvement in reference frequency (fref)-related spurs as seen with the LMX2594?

Thank you in advance for your time and expert guidance.

Best regards,
Mark