Hamish,

Lifetime memberships are like lifetime warranties, only for the life of the member of the item, which ever is shorter.

I used to belong to a professional organization that suddenly started pushing us to sign up for life memberships. . . . . I didn't, (didn't have the cash at the time). By the end of the year they were bankrupt!

Any life memberships I buy now, I consider a gift. (At my age it isn't wise even to buy green bananas)

I am not suggesting that the STA will do that. Just giving my own experience.