I've been running something similar on my three Raspberry Pi 4 with microk8s and flux [1]. Flux is great for a homelab environment because I can fearlessly destroy my cluster and install my services on a fresh one with just a few commands.
Next on my list is set up a service mesh like istio and try inter-cluster networking between my cloud cluster and home Raspberry Pi cluster. Perhaps I can save some money on my cloud cluster by offloading non-essential services to the pi cluster.
I'm also curious about getting a couple more external SSDs and setting up some Ceph storage. Has anyone tried this? How is the performance?
One of my pain points is the interaction of the load balancer (metallb) with the router. It seems to want to assign my cluster an IP from a range, but may choose different ones at different times. Then I have to go update the port-forwarding rules on my router. What solutions do you all use for exposing Kubernetes services to the internet?