@K_Siman thanks for all the help!  One thing I did notice, however, was that one of my employees ended up earning 0.08h OT on a completely different project, but when it exported, QBO assigned it the Prevailing Wage OT rate, rather than the regular OT rate.  In this particular case, I don't have a problem letting it ride because it's such a small amount.  However, I am concerned that this mapping override did cause an error with the OT rates.  I double checked and the regular mapping does show that the Overtime field is selected to Overtime Pay, and not the Prevailing Wage OT alternative rate that I created and assigned to the employee.