Thanks for reaching out to the Community, LeesaMobile.
I can certainly understand how an ability to turn off warning messages about serial numbers while creating invoicves could be useful and have submitted a suggestion about it as of today.
You can also submit your own feature requests while signed in.
Here's how:
Your feedback's definitely valuable to Intuit. It will be reviewed by our Product Development team and considered in future updates. You can stay up-to-date with the latest news about your product by reviewing Intuit's Product Updates webpage.
As a workaround, you can dismiss when when they display for you.
Please don't hesitate to send a reply if there's any additional questions. Have a great Thursday!