Tricky, tricky, tricky, if I may quote a favourite witch.
The two tier element is coming into being via the one thing that will lure everyone in nicely - socialising with alcohol, the easiest, legal, cheapest and most damaging thing to health and social issues. (Holds up hand, yes, I'm a rank hypocrite who indulges, but am trying to think big picture).
Small independent pubs with limited capacity will have to do this or massively lose income, or will close because they can't keep up with big chains and all their food options, promotions etc etc. Big chains will do it, because increased profits.
How long before some wag hacks the system rendering it meaningless? How complicated would the security measures have to be?
And wearing my best conspiracy hat ever, what if people go a bit nuts - I can see drinks promotions left right and centre, people go giddy with excitement after months of stir craziness, and inadvertently (or by design) cause public disorder in the summer months? Oh wait there's a bill for that, and there will be your proof it was needed.
Like I say, wild speculation, but oh my, the potential aside from the virus itself....