Hudson's chum knows his business, but from the perspective of another performance Engineer.
It is not permitted in certifying an aircraft for Vref to be less than 1.3Vs, (again in CAS, not necessarily IAS) - but in light aircraft particularly it may be best practice to use something higher.
They never do in airliners because Vref determines landing speed determines runway length determines the number of airports it can use. So, airliner manufacturers do everything they can to bring Vs down and thus keep Vref as low as possible.
Light aircraft rarely have this problem so a good approvals team may well decide to go for a higher Vref. In microlights, where it's far easier to lose speed, Vref of about 1.7Vs is not unusual. The bottom line is that the aircraft must touch down just before the stall, not just after!
G