As mentioned, exceptions can be specified before the house is shown. I didn’t want to remove the Nest Protects. So I specifically noted with the listing agent that they would not be included with the sale. I don’t trust that they can be fully separated from my main Google account.
The new owners will get non-smart smoke/co alarms in their place.
In Germany the whole floor is tiled, not just up to the cabinets. Germany's a bit extreme, I've never seen that in the UK. But everyone does it, so the new owners come in and have their old kitchen refitted into the new house - it's just what they expect.
When we moved to Germany, the company included a "kitchen bonus" at signing on, so that you could buy a kitchen, because as foreigners you would not be on the kitchen merry-go-round!