Fun fact, since the adoption of the international yard back in the 60’s the only official definition of an inch is 25.4mm - it’s quite literally just a conversion factor of metric
In most of the aviation world (always exceptions like the US) we mix and match a lot… altitude is in feet, speed in knots, distance in nautical miles, runway length/width in meters, pressure in millibars/hpa, temperatures in Celsius, fuel in litres and Kilograms etc etc.
I feel much of the UK is very similar - in normal life I’d state my height in feet, large distances in miles, speed in mph, but small distances in cm and mm and small weights in grams and kg.
To me the UK already doesn’t limit itself to the metric system… I don’t see why there’s a fuss. Metric is clearly superior when it comes to science and engineering, for everything else I couldn’t really care less!