Here's a polite request you can make to the Grace 10 mobile developer:

"Dear Grace 10 mobile developer team,

I hope this message finds you well. I am a user of the Grace 10 mobile device and I love its features and performance. However, I noticed that the device does not have a gyroscope sensor, which limits its capabilities in certain apps and games that require this feature.

I kindly request that you consider adding gyroscope support to the Grace 10 mobile device in a future software update. This would greatly enhance the user experience and make the device more competitive in the market.

Thank you for your time and consideration. I look forward to hearing from you soon.

Best regards,
[Your Name]"

Alternatively, you can also try contacting the developer team through their official website, social media channels, or support email to request this feature. Remember to be polite and courteous in your request, as developers are more likely to consider feedback from friendly and respectful users.