I don't know about the UK trims or value, but in the US the 40 is not holding its value really well. But to be fair, that's mostly because of all the rebates and credits on the new version.
KBB says my one year old 2018 is valued at around 18k. I think the MSRP was upper 30's.
BUT in my area you save as much as 14k with credits and rebates, which helps you buy it new, but hurts resale. Who would buy a used when newer is cheaper? Hence the lousy resale.
2018 Leaf SV Pearl White with Tech and All Weather, Purchased New on 5/3/19