Thanks Taz. I looked at the link you sent, and the only mention of SN access to storage is:
Your super neighbour will NOT be able to...
use the Purple Freestyle Farm Designer to buy any Farm Cash items or use any FC items in your storage.
I think it used to work like this... a SN couldn't put gift/coin items in storage for their neighbor, but they could retrieve them from storage to put on a farm.
It doesn't appear to be working now. SN can see what is in their neighbor's storage, but is not able to place those items on said neighbor's farm.