just buy it, end game grinder for us peasant. even if gbp drop, the delivery import charges went up, so not much saved then 2-3 years ago.
another thing you can try with your sette is when you change grind settings, run the grinder, change few notches, run grinder and repeat until your desired settings.
tiagong this to expel grinds currently inside that blocked your burrs from going finer. so while your markings show finer, the burrs do not tighten as much. at least what i saw with NZ when i did this