Good thread, I’m also looking at the same for a house we haven’t moved into yet but that’s another story.
As for the light switch polling the server, I would imagine that is to allow the user to register at the server in order to control the switch across the web. The way this works is you send an instruction to the server which is polled by the switch. As the conversation between switch and external server is initiated by the switch and therefore inside your routers firewall it can retrieve the instruction, without the polling your router wouldn’t allow anything incoming.