Q1: Do you use this extension currently? [yes/no] NO
Q2: Do you plan on using the extension in the future? [yes/no] NO
Q3: Should UAs implement the extension? [yes/no] NO
Q4: Can you briefly describe your use (or planned use)?
Q5: Your cited affiliation? (website, service, company or whatever describes you best)https://3dthis.com
Note: I think device specific infos add useless complexity. A standard should not be modified by devices capabilities.