US Immigration from Cambodia

I am referencing the K1 flowchart:

In #8, it says that the embassy will send forms and checklist to the beneficiary. Is this still accurate? I posted on here earlier this year asking about changing beneficiary mailing address and was told it doesn't matter because they won't be sending anything to them.

I just moved and I need to change my address. However my petition is already on the way to the embassy. Do I change it with USCIS, the DOS, or both?

Today I received an email from DOS with the FTP attached. It's dated with today's date. I just called the NVC to get the Invoice number so I can log into CEAC. I called at 2000 EST (8pm) and was answered on the first ring(after the phone tree), I didn't have to wait at all. The person who took my call provided me with the invoice number and told me that the case had already been sent to the Embassy! I logged into CEAC with the case # and invoice # and it already shows "IN TRANSIT". I did the DHL hack (thanks @Greenbaum) and it shows that it is already on the way and should be delivered to the embassy Monday. I was completely caught off guard, I was really expecting it to sit at the NVC for months. I just emailed the embassy to ask if they are actually processing and interviewing and am awaiting a response.