We already have the feature 'Persistent Trouble Notification' to get alerted until the errors are rectified for your down/trouble monitors. The number of persistent notifications for a monitor for a downtime is 30.
Please follow the below steps to configure a persistent trouble notification for your server monitors:
1. Login and go to Server > Server Monitor > Servers > click on the server monitor to which you want to set up this notification.
2. Hover on the hamburger icon beside the monitor display name and click Edit.
3. Under Configuration Profiles, click on the pencil icon beside Notification Profiles.
3. In the Edit Notification Profile window, click on the drop down under Persistent Notification and select Notify on every error
4. Save your changes.
With this setting, you will be continuously alerted, thus generating frequent alerts.
Hope this fulfills your requirements. Let us know for further specifications or queries, if any.