You could have local switches, that's what I've got, but it's not what I'd choose if I was wiring from scratch now.
It just makes your network overly complicated, added connections, added overhead. If you've only got a switch connected to a switch, it's not that bad, but why not just do it properly whilst you've got the chance?
If you've got upwards of 4 devices in one position, then by all means, have a switch there, but a 48 port switch in a cabinet, with your modem, maybe a NAS etc, definitely the neatest way to go.
And yes that's a joke, Eric always posts a post about X-Pole RCDs, that auto reset etc, etc. Not that I've ever seen one for sale, or in the wild. I can't even find one on google. Don't worry about it.
I do think there are better options for energy monitoring than something in your consumer unit though, a wifi connected energy monitor would probably be much more useful (depends where you're putting your CU I guess)