Hi, Mookey_V!
Thanks for reaching out to Microsoft Community and posting your inquiry regarding the warranty of your Surface Book 2. We understand you wish to extend its warranty, hence, the reason you took the time to let us know about this. We appreciate you allowing us to help you out here.
For additional coverage, including accidental damage coverage, Microsoft Complete can be purchased within 45 days of device purchase only. I am afraid that this is a one-time purchase only. Kindly refer to this page to know more information regarding Microsoft Complete for Devices Terms and Conditions.
This may not be the message you wish to read, we hope to have helped you out with the needed information regarding your concern.
Kind regards,
Janette_Z