There is an issue about any earth terminal must be used.

This created hilarious situations with Masterseal plastic boxes having
a brass terminal which were intended for loop-in earth use, rather
than someone adding an earth to earth the terminal.

Some councils still insist on it, can not recall the reg in 17th, but
it prompted MK to specifically state they need not be connected and
later on to remove them for a time. Someone nit-picking. Another nit-
picking is the various IPx4 fan heaters for kitchens/bathrooms/toilets
- they are actually German to IPx3 but get re-written to IPx4. Dimplex
deceitly boast about how their new fan heater is IPx4 when the old one
was labelled IPx4 with an open fan cover on the lid (the new one is
somewhat shielded).