In Torque 3.3, the description of the attribute idMethod is
idMethod (idbroker|native|none|null) "null"
There is no reason to have the explicit value "null". As with other attributes (e.g. "default" on element column), leaving the attribute empy is more intuitive than having the string value null.
Therefore, the suggestion would be to change the definition to
idMethod (idbroker|native|none) #IMPLIED
or its xsd equivalent.