We have a loan that will be fully secured by a Certificate of Deposit. The lender is also taking a lien on the customer's primary residence as an "Abundance of Caution". In this case, what do we put for the Property Value on the LE and CD since an appraisal / evaluation is not required for an "Abundance of Caution."

Whatever you estimate it at.

This use to be a common occurrence in order to make the interest tax deductible, but with the new tax law and depending on what the funds are going to be used for, likely this was a waste of time on both the bank and customer's part. Why would a bank agree to or feel a need to do this on a fully secured CD loan??

Ditto. The only thing the Abundance of Caution exempts you from is the Appraisal Rule. It still requires you to abide by TRID, Flood, ATR, RoR, etc. It's not worth it from a Compliance standpoint if the collateral is really just an AOC.