[tweetiepooh]

Chip/trace - not likely needle too fine to do that covertly. Used for some other purpose - possible but not likely.
The PM has already said they don't plan to have CV Visas. How would you prove you have been vaccinated? Don't carry a phone all the time or lost it or stolen or broken?
The plan as detailed makes things simple, if you try to add race into it that gets really complex and not likely to help.

Age is easy to work on but race/economics? You could end up with hundreds of tiers based on age, health, race, deprivation. On the last where do you put the divisions.

With race it's been mooted that the death rates are higher because many work in front line jobs (health care for example), well they are covered in the plan.