I would like to do a Backstage design without writing code, the syntax of XAML is confusing and I do not understand it well, besides being slow, the development of software at design time is always much faster.
Thank you for sharing feedback with us. We have already logged an item to improve the design time support of RadRibbonView in our backlog. I will update and merge the information in the description with your suggestion and I will decline the current one. You can track it on the fallowing link: https://feedback.telerik.com/Project/143/Feedback/Details/113168-ribbonview-implement-ribbonbackstage-design-time-support.
I cannot commit to a certain time frame for this feature, however, you might find useful our guidelines from the documentation: https://docs.telerik.com/devtools/wpf/controls/radribbonview/gettingstarted. If you come across any further issues, feel free to open a new support ticket and we will gladly assist you.