There are some HPC environments that use Kubernetes but they likely use custom schedulers optimized for batch workloads (e.g. https://www.amazon.com/Kubernetes-Running-Dive-Future-Infras...
I'll email you to follow-up since tracking HN comments isn't a great way to have a conversation.
FYI: the person you are responding to is the author of Kubernetes The Hard Way [1], which is effectively a tutorial of learning how all the K8s pieces work together. He also co-authored the first book on it [2]. He's also a Google employee, but I would trust his opinion more than others just because he's probably seen more use cases than anyone else.
https://www.amazon.com/Kubernetes-Running-Dive-Future-Infrastructure/dp/1491935677 Appndiex A has Building a Raspberry Pi Kubernetes Cluster section. It discusses to setup iptables to route eth0 to wlan0, changing cpu type to ARM from AMD64 flannel, etc. May be of use.
I'll email you to follow-up since tracking HN comments isn't a great way to have a conversation.
For K8s, this book is from some of the k8s authors themselves - https://www.amazon.com/Kubernetes-Up-Running-Kelsey-Hightowe...
[1] https://www.amazon.com/Kubernetes-Running-Dive-Future-Infras...
https://www.amazon.com/Kubernetes-Running-Dive-Future-Infras...