A challenge to an approved-source restriction in a solicitation must be filed before the deadline for proposals, or the protest may be deemed untimely.
Source: Protest of Approved-Source Restriction Must Be Filed Before Proposal Deadline – SmallGovCon
SBA Updates All Small Mentor-Protege Template with Affiliation Questions
With little fanfare, the SBA has updated the template for agreements under the All Small Mentor-Protégé