In this first version you can select "Create new wallet" > "Multishares backup", then you have to select your backup schema n-of-m, and then instead of showing you 12/24 worlds it displays `m` sets of 33 words to backup. Then you will need `n` of those sets of 33 words to recover your wallet.

Technically, this is an implementation of the Satoshi Labs SLIP39: https://github.com/satoshilabs/slips/blob/master/slip-0039.md

Matechamically, I know you know but it is based on Lagrange polynomial interpolation.