When trying to determine future value of a loan with compound interest
and frequent deposits, if I determine the EFF%, then do I just set my
calculator for one compunding per year? (12% nominal, compounded
monthly, 12.68 EFF% once per year?)

12.68% seems reasonable for an approximation, but the value of the
equity vs the balance due and the credit rating of the barower are
important factors reguarding the future value of a loan. More details
may help you get a good answer.   Neil

Thank you for your feedback, this a question I have about a homework
assignment.  The givens are simply nominal interest, a series of
payments, monthly compunding and the task is to determine the amount
in the account at the end of the series of deposits.

I think I need to set my caluculator to one compounding per year since
I've allowed for the compounding by changing the nominal rate to an
EFF%.