Hi Chris,
We have reviewed your query, and unfortunately, there is no built-in support for JSON syntax in the edit control. However, you can create a custom language to work with JSON syntax. We have attached a sample for the edit control that includes a custom language section, which you can refer to for guidance. To learn more about creating custom languages, please consult our User Guide regarding custom language support: https://help.syncfusion.com/wpf/syntax-editor/language-support/custom-language-support
If you have any further questions or need additional assistance, please feel free to reach out.