I think all the 1901 seats are linked to an actual person with a FAN number - same as STs.
Whether that person is always a ‘fan’ I don’t know, but the vast majority of 1901 members are regular people who accrue loyalty points in exactly the same way as everyone else.
They don’t get priority...
1901ers don’t get priority access to purchase away tickets. That isn’t included in the premium they pay.
They can pass tickets on to a named person - that’s the perk.
They are in the same points brackets as everyone else.