I hope Harvey sticks around and grabs a cookie at some time.
I've loved (and sung) his material for 30 years or more, although I learned "Hey Sandy" initially from Colin Scot, so it had already had a bit of "folk process" applied.
I must confess to altering lyrics - most singers do. Sometimes it's a lapse of memory on my part, sometimes it's a pedantic restoration of a disregarded subjunctive or other grammatical error in the original, sometimes it's a necessary (to my mind) updating or gender swap. However, I always try to make my interpretation as true as possible to my perception of the author's intention.
Harvey's songs never seem to need alteration, and sing well "out of the box", so I can see where he's coming from in his posts.