Residual UST: Please offer some clarity on this

Do mentions "New $LUNA will be airdropped to $LUNC(old $Luna) stakers, holders, residual UST holders, and essential app developers.

Would like to have more clarity on the definition of “residual UST holders”.

If someone who has some background information could clarify about whether or not a snapshot will be taken upon the new launch of $LUNA and where/when this snapshot would happen–this would offer some clarity as to what current $UST holders should be doing with their funds.

Does this snapshot account for wallets on non-native chains? For example: (Wormhole UST held on Metamask Ethereum Network).

Would these people off chain have to transfer their off-chain $UST back onto Terra’s chain prior to a snapshot?

If anyone can offer some clarity on this it would be appreciated greatly