I've been working on adding database actions for FB3. One action is to run a stored procedure using ADO. The property page (ie. the design time editor) is worth having a look at.
Connection String - enter an ADO connection string or let the wizard build it for you.
Refresh - will load the available stored procedures of the specified database.
When a stored procedure is selected, the parameters are retrieved and allows you to set the parameter input value (which also accepts variables) and set output value to a variable.
If the stored procedure returns a result set, then this can be saved as an xml file to disk as well as output to the FinalBuilder log.