How to Allow Customers to Add Custom Notifications to a Shared BPMN in Camunda Using bpmn-js?

Hello everyone,

We are using Camunda as our workflow engine and BPMN-js to visualize our BPMN diagrams. We are developing a SaaS where all customers use shared BPMN models. Whenever a client requests a “notification service”, we manually update the BPMN, add the notification service at the desired location, and modify our factory class to ensure that the notification is only sent if the customer is included.

The challenge:
We want to give our customers the ability to add their own notifications to the BPMN using bpmn-js without modifying the original shared BPMN models. The solution needs to be generic and not affect other customers.

Our current approach:

Open the BPMN.
Add the notification service in the desired location.
Update our factory class to send notifications only for specific customers.

Requirements:

-Customers should be able to add their notifications dynamically using bpmn-js.
-The original BPMN models should remain untouched.
-The solution should be generic and not impact other customers.

What we’ve considered:

-Custom overlays or extensions in bpmn-js.
-Dynamic injection of notification tasks at runtime.

Has anyone faced a similar requirement or can suggest a best practice approach to achieve this?

Thank you!