Oh, one other comment about
Blockquote
I was hoping I didn't have to change the model itself and write the value directly to the temporary state (maybe via a query),
You can just run the query, but there is no way to pass a parameter back with that query like you normally can using additionalScope. I have a feature request for exactly that which will simplify things quit a bit. Please heart it and +1 it to get it some more traction!