When generating SQL in the Query Builder we have an option to use Quoted Identifiers.  When this option is enabled, the Aqua Data Studio defaulted Quoted Identifier for that database is used.  The default value is a value which is determined by AquaFold and is not changable.  It is determined in the UtilScript.java.  The default value for Sybase ASE, Informix and Generic is EMPTY, meaning we don't use Quote Identifier.  So, for Sybase ASE you can enable the option in Query Builder, but no Quote Identifier will appear.  Sybase ASE users have never complained because Sybase ASE users don't use Quote Identifiers for object names.  Reason we choose empty string for quote identifiers in Sybase ASE is because Sybase ASE has the "set quoted_identifier" option, and also has the _bug_ of messing up the name of an object when using double quotes and the name is too long.