KillerK

Confirmed bug...

https://github.com/unraid/api/issues/1914

Concluding this thread now and answering a couple of my own questions hoping others might find it useful.
What is classed as excessive?  In my testing anything over 1 read per minute of the flash drive would be excessive. Where my results above a concern?  Yes, as they exceeded the above and at worst were over 200 reads per minute. The resolution was to apply the /boot/config/fastusr config which @Kilrah kindly confirmed.
 
I did retest my scenarios today by again removing the nginx rate limit alteration and re-ran with and without the fastusr fix.  I my usecase I pushed the ZFS Arc to the max, kept the server busy with various activities and managed to replicate the issue by then browsing the unraid UI which by then slow which then started to notch up the read counter on the flash drive.
 

***Health warning*** I'm still learning k8s so there may be concerns with my solution. 
 
My reasons for doing this were to get away from using minikube on my Windows workstation, the course I was following was written for linux hosts and I was fed up with having to hack around the material to work in Windows.  I had my unraid server with both docker and kvm enabled so I wanted to be able to follow the courseware using that.
 
So after lots of failed attempts and reading I gave up with attempting to get minikube to use a macvtap network, I don't believe its possible by design.  Instead I focused on how to get the dashboard accessible via the bridge networks using minikubes docker or kvm2 driver.
 
Start minikube on the unraid server as normal (--force needed as unraid is root by default which minikube complains about):
minikube start --force --driver=docker  
We cannot use the minikube binary to invoke the dashboard as there is no way I've found to enable remote access/get the local proxy instance listening to anything other than 127.0.01.  So to bypass minikuke first manually enable the needed addons:
minikube addons enable dashboard minikube addons enable metrics-server  
To then get to the k8s web dashboard from a remote client, instead of running 'minikube --dashboard' use:
kubectl proxy --address=0.0.0.0 --port=freeport --accept-hosts='.*' This does allow you to configure the proxy to accept remote connections (--address=0.0.0.0) and means the dashboard url (http://unraid-server-ip:freeport/api/v1/namespaces/kubernetes-dashboard/services/http:kubernetes-dashboard:/proxy/) will now work with clients on your local subnet.

Erm I recall a lot of Win11 nonsense with SMB shares.  When you get an error msg on Windows do a logout and login again and I found the shares were then accessible.