Hi Graham,
Thanks for your thoughts, I had seen the MRI tool but it’s static analysis so not terribly useful for my purpose.
Zipkin / Sleuth / Opentracing / Jaeger / Census / Pinpoint etc are all tools attempting to do the same. I suspect there will be many more to come as the distributed tracing market is starting to emerge. Main thing I retained is that there is no all encompassing tool (and never will be) that is going to give you 100% insight into everything on the button, custom development will always be required. A framework like Axon could provide generic tracing hooks (command received, dispatched, AR / Sagas invoked, EventHandlers called etc) that would make it easier to plug the tracing infra. Again I remember vaguely something being in the pipeline for 3.x, hoping Allard will chime in on this 
As far as the anomalies and errors go you might be able to leverage something like prometheus, but the tool will only ever be as good as the metrics you provide it with. Thanks for linking your blog btw, it’s very insightful !
Jorg