I hadn't realised the fanzone is a sort of mini festival thing too. So they have a stage for concerts, bingo nights, drag sessions 
, author talks and whatnot when the football isn't on - and stalls selling food and drink. They say it's "largely seated" but I can't see how that kind of thing would be policed, as presumably you're encouraged to walk around to see the various acts and stalls and so on. It's all outside, I think, so unmasked. So in that sense I can't see how it's worse than one of those big outdoor beer gardens that have sprung up, though without the 2hr limit - or even any big park on a sunny Saturday.
I assume now that the "ethical issue" is that you can't require people who have come to watch the football test, while not demanding the same thing from a family who've come to watch "draw with Rob". But also, I can see an argument for having two separate events - the football where you have to show a test, but can then drink, shout, sing, dance the conga with whoever will have it, and lick your neighbours if Scotland score... And then "everything else" with no neighbour licking, but also no test, and a bit more standing apart from each other in food queues.
Obviously at some point we'll have to move back to more freedom in what we can do. And it would be lovely to be able to do spontaneity in public without needing tests beforehand. But if this is being treated as a "test event" like they did in England, I don't know how they are going to judge if it's been a success or not, and that "this kind of thing" is actually safe? I don't want to advocate for reduced freedoms at all - and I confess I do seem to have some internalised anti-football bias 
as testing doesn't seem reasonable to me for a "family day out in the open air to listen to some light jazz and have a picnic" as it does to have 6000 football fans together to watch the game. Even with added beer and wine. I just don't trust the football people not to fuck it up