"If Sofco stands, any pension plan's use of the Segal Blend in withdrawal liability calculations may affect the accuracy of pre-withdrawal estimates, the amount of withdrawal liability assessed, the posture of any settlement negotiations and arbitration proceedings and even the efficacy of any previous settlement agreements entered into with the pension plan.... Additionally, the opinion discusses clear boundaries on the deference accorded to pension plan actuaries to determine the appropriate interest rate to use in withdrawal liability calculations." [Sofco Erectors, Inc. v. Trustees of Ohio Operating Engineers Pension Fund, No. 20-3639 (6th Cir. Sept. 28, 2021)]