You were asking the wrong people the wrong questions hence the response you got. Also you need to be very careful with the words you use and the kind of questions you ask when you meet the the IOs. If you take a look at my previous response, you will notice I never said anything about the expediting request you spoke of, instead I said 'nothing wrong with doing an INFOPASS to find out the status of your application'.
I didn't use the word 'expedite' on purpose simply because I don't think you're at the stage where an expedite request is applicable to you. The people performing the biometrics have no access to the AOS files or what the AOS petition is based on, so asking them about the KCC case file or making an expedite request will no doubt result in some confusion or wrong response like you found out.
If you need to do an INFOPASS appointment with your FO, go ahead and do that. When you get there, you can ask if you've been scheduled for an interview yet, you can ask if your background check has cleared. You can even ask if your case file has been requested from KCC. You can politely explain about the need for your petition to be adjudicated before the FY ends or they run out of visas. However, I would recommend you don't go there demanding for them to expedite your case. Expediting a case is not a right, they're not required to approve the request even if it gets made.