I don't think we need to do this with destination charging. That's the whole point of it.
So what if someone is 'waiting' - they can't be that much in a hurry if they're wanting to use a 7 kW charger.
They don't need to be in a hurry as such, but if I'm out and about and pull up to plug in at a destination charger it would still be useful to know if the person will be back soon.
As you say, it still won't make a huge difference as I'm unlikely to be running on sparks at that stage, or I'd be hitting up a rapid rather than a 7/11kw charger.
But I have requested and been requested via the needtocharge app on a destination charger.
When I contacted someone else they replied that they were just coming back and would be there in 10, so I waited as I was in plenty of time for the cinema.
Last week I received a request, I replied that I had just sat down to lunch and wouldn't be back for about an hour. They thanked me and just parked in a normal space as they didn't have any great need. But they were still able to check.
I've also used the system to alert a driver to a pending parking ticket so it has other uses too, lol.