If the profile of a tyre is different, then the size is different.
You don’t have to have matching tyres for the UK MOT, and there isn’t really an issue. And there is no compunction to stay with the manufacturer’s original speed rating. Its not recommended, but not illegal. It has not lead to spectacularly unsafe cars.
The use of the 'stan term seems OTT and provocative.
Resident tyre expert says even a H-rated tyre would be on in the UK, on the basis of speed rating.