The ERO Firm's address prints on the return...the address that's attached to the EFIN that was issued by IRS.  You cant change it without changing it for the EFIN. 

EFIN's are are only good for Efiling returns from a specific address (the one on the EFIN application)....are you Efiling returns from an address different than the ERO?  or are you submitting the returns to your ERO and they are Efiling from the ERO address?