Yes, ARFID is still very little known. It is diagnosed in some parts of the UK now, but still not all. And from what I have seen in the groups mentioned in this essay, diagnoses are extremely difficult to get.
The general advice for ARFID sounds similar to what you advise regarding autism and food difficulties - the less pressure, the better. Part of my wanting to write this piece was to express that as I know if my mum and step-dad had known that information sooner, it would have spared me a lot of trauma and moments I wish I could erase.
But I am surprised that the USA isn’t more aware actually! I have spoken to some people who have ARFID (not sure if diagnosed or not, admittedly) who are in the States!