I would like to put a link to a Change or Request in a notification without using the Process approver feature i.e. a hard coded url which will open in a specific module.
This can be done quite easily by specifying the full url in the notification. Here is an example for Change:
To create a link to a different module i.e. Request, you can change the class_name to the specific module i.e. for Request Management - RequestManagement.Request
Be aware that by not using the Process Approver system setting, if the server name changes you would have to modify each notification rather that the single system setting for Process Approver.