@Frank_Kohne
Using Kafka is basically the same purpose.
The reason we use the ELK stack was purely for compartmentalizations of systems and we were not building a product. Your bpmn.ai looks like a product thus makes sense you implement custom features that meet your strategy. For us it was about being able to use “off the shelf” tooling to provide the end result: basic reporting and ML capabilities.
Similar use case for: Prometheus Metrics: Business purposed process engine plugin