Looking at the Express newspaper article, it is a trial in one airport only at the moment. Which is why probably no one here has experienced it yet.

In theory great, like the use of biometric passport, fast automated entry control for EU passport holders in UK. Great, fast, easy...until the machines broke down and it seemed that they were never repaired.

A thought on negotiation. Very often the employer has little to no room to negotiate on pay. Pay can be fixed by higher authorities, and/or it is something where nobody wants to start setting new precedents. Getting hung up on pay is often a dead end.
However there is often room to negotiate on other things. Scheduling is one area. I always asked for, and mostly got, all of my hours pushed to one end of the week.

This gave me all my days off together, instead of split. This has a financial advantage as well, as there are fewer days with travel expenses.
Some schools will allow a small budget for you to buy training material, where you provide receipts they reimburse you. They can claim this against tax, so no cost to them, and it save you from covering the cost (or not doing some valuable activity).

Some schools will pay a small bounty for further training. For example, I know one school that will pay you 400 (once per year) if you complete agreed Coursera courses. These will increase your career/personal development, and will also improve your prospects for the future.

From my own experience, jobs that have more responsibilities, require greater skill sets (e.g. curriculum development, course design) or where you are teaching towards internationally recognised qualifications (e.g. GED, IB, IGCSE, AP) will pay better. But there often is still limited potential to negotiate.
However, being a more qualified (not just certs.) teacher increases the number of higher paid jobs you are eligible to apply for.

Last sentence of my last post above should end... a few for summer if you re-sign (as in sign on again for the following year).

Almost finished :-)