In NounsDAOLogicV2.sol, NounsDAOV3Admin.sol, and NounsDAOLogicV1Fork.sol, the minimum proposal threshold can be set as low as 1 basis point.
https://github.com/nounsDAO/nouns-monorepo/blob/718211e063d511eeda1084710f6a682955e80dcb/packages/nouns-contracts/contracts/governance/NounsDAOLogicV2.sol#L61-L62
https://github.com/nounsDAO/nouns-monorepo/blob/718211e063d511eeda1084710f6a682955e80dcb/packages/nouns-contracts/contracts/governance/NounsDAOV3Admin.sol#L111-L112
https://github.com/nounsDAO/nouns-monorepo/blob/718211e063d511eeda1084710f6a682955e80dcb/packages/nouns-contracts/contracts/governance/fork/newdao/governance/NounsDAOLogicV1Fork.sol#L118-L119
This could pose a precision issue even if the total supply of Nouns tokens is already in its three digits. Apparently, a proposal threshold determined via the following two functions could return zero, e.g. (1 * 720) / 10000 yields zero due to truncation, i.e. the numerator smaller than the denominator.
https://github.com/nounsDAO/nouns-monorepo/blob/718211e063d511eeda1084710f6a682955e80dcb/packages/nouns-contracts/contracts/governance/NounsDAOLogicV2.sol#L921-L923
https://github.com/nounsDAO/nouns-monorepo/blob/718211e063d511eeda1084710f6a682955e80dcb/packages/nouns-contracts/contracts/governance/NounsDAOLogicV2.sol#L1066-L1068
