Github user aljoscha commented on the issue:
https://github.com/apache/flink/pull/5573
I can't comment on the first points but on the last point. I would suggest
to only add `getAccumulators()` to `RestClusterClient` that behaves the same
way as the existing `getAccumulators()` on `ClusterClient`: it retrieves the
serialised values and returns a map of the deserialised values.---
