For those of you who have paid for the NECO supplemental fee, did you wait for an e-mail or just go directly to the website and pay for it? (They don't ask for my application ID so how will they know I paid for it?)
What I did was pay through PayPal, and in the note to seller I wrote "This is the application fee for "futureusaeyedoc", OPTOMCAS ID 1234567." I was unsure about it also, but when I called them they said that I was good and they had received it!