We got an ovo smart meter about this time last year. The IHD thingy is plugged in but rarely gets used, not least because I don’t trust the numbers it gives in the history view; on the 10-day view the amount you’ve used on certain days seems to change as the day recedes into the history which is a bit weird. It also defaults to a pointless screen that just says how much you’ve paid since you had the thing installed, rather than the real-time page or something actually useful.
The “usage” bit on the website changes a bit to show the greater level of detail available, but there’s no way to get hold of the data yourself that I’ve found.