How can UK SVFR allow access below normal VFR weather minima, when for UK one requires 10km / 3000m (if instrument qual held) vis for SVFR?
Instrument rated pilots have no such minimum vis. Minima for ATC to issue SVFR clearances for departures vary a little between airports I think, but usually can be issued down to 1800 m met vis and 600 ft ceiling. There is no requirement for a SVFR flight to maintain a particular flight visibility, just clear of clouds.
But even 3000m is "below normal VFR weather minima".