Hi Matthew,
Thank you for using Syncfusion products.
We have checked the reported query “Apply styling to only a part of the message” from our end. We would like to let you know that we have provided a feature from which you can apply custom template for the text message using TargetStyle. The feature will be available from next nuget release. You can also customize your message using MessageTemplate, please refer the following online documentation for more details,
Please let us know if you need further assistance.
Regards,
Chandrasekar Sampathkumar