The Salesforce node is missing an important field. It pre-populates the standard fields so you can easily make a query without having to program.
However, the field AccountNumber from the object Account is missing from this list. I believe it only needs to be added to the configuration file for Account.
There is a reference for this object (with the missing field on top):
Now I am not able to use this field without writing a custom full SOQL-query.