As Traders are still needed to transfer gold ingots to the Trading Post (but somehow the inverse works instantly without them???), that should be their highest priority before any resource transfers.
It would also be very useful to be able to set a single priority resource for them to stock, rather than having to mess around turning off all other resources they are supposed to stock.
Finally, other than immediate personal food or water needs, Trader Workers should not do any “Shelter Stocking” as there are pretty much always going to be lower priority, less time sensitive workers living in the same house which can handle that.
Just like how soldiers and guards should never consider any other activity while engaged in battle, even food and water in that case.