Technically there is no signer on a Beneficial Ownership Information Report. However, FinCEN does have guidance on who can file a BOIR - anyone that's authorized to act on the Company's behalf for this purpose.

From FinCEN:

Anyone whom the reporting company authorizes to act on its behalf—such as an employee, owner, or third-party service provider—may file a BOI report on the reporting company’s behalf. When submitting the BOI report, individual filers should be prepared to provide basic contact information about themselves, including their name and email address or phone number.

This is also true of companies created in 2024 or later that cease to exist. They must make arrangements to have someone authorized by the company to make BOIR filings, even if they have ceased to exist before expiration of the 30- or 90-day period reporting companies have to report their beneficial ownership information to FinCEN.