Little update.
As proposed here:
We tried to eliminate “large overviews” which many agents have access to.
Specifically the overviews all tickets and all closed tickets were available to everyone.
In a short time we surpassed 5k tickets there which made that overview mostly pointless but we forgot to remove them.
At the same time this overviews seemed to put a high load on the host PC.
When disabling them average CPU usage was nearly halved and system stability has improved so far.