Hi HazelNuts39,
why would it need a different treatment of stall speed?
A conventional aircraft stall speed is demonstrated by trimming the stab only as far as Vref, then decelerating at 1 kt/sec whilst applying back elevator until the nose drop. It was found that this always produced slightly less than 1g (94% ish) at the measured stall speed value.
In Alt Law, the Airbus continues to trim and level flight was achieved right up until the speed where you will lose control - all apparently done at 1g.
See page 36:
http://www.skybrary.aero/bookshelf/books/2263.pdf
"Airworthiness Authorities have agreed that a factor of 0.94 represents the relationship between VS1g for aircraft of the A320 family and VSmin for conventional aircraft types."