Feedback from customer is that it is not very obvious which instance type raised the custom check due to the styling of the instance information
The following is for example shown:
ServiceControl Health reported by Particular.xxxxx.xxxxx on MYHOSTNAME 4 minutes ago
After discussing this it would be more obvious is custom checks would be grouped by an instance identifier with sub items for all its failed custom checks or at minimum adjust the styling that the instance identification is better to read.
For example, an improvement would be a font color that results in a higher contrast different and to use bold for the identifier and format string:
Reported by Particular.xxxxx.xxxxx on MYHOSTNAME (category: ServiceControl Health) 4 minutes ago