I remember the following blog post about index vs type discussion:
Especially one statement:
Do your documents have similar mappings? If no, use different indices.
IMHO, this applies to the different modules because only a few fields match with each other. Therefore, I'm wondering how does the current approach in metricbeat really scales in terms of memory/disk usage. Of course, I could update this within logstash and route it to different indices but then all dashboards are broken. What do you recommend?