"[T]he DOL has issued proposed regulations that represent the most comprehensive changes to the DBA since 1982.... The proposed regulations would require contractors to annualize ... all fringe benefit contributions, including for 'defined contribution pension plans (DCPPs)' to determine the hourly equivalent for which they can take a credit against the fringe benefit obligation.... For both funded and unfunded [fringe benefit] plans, the proposed regulations would also require an employer to pay any amount that an employee has been underpaid (including earnings) to an employee. In addition, employers would need to notify employees of the fringe benefits being paid and would need to ensure that the plans are properly funded."