In general Zing implements the entire Java Standard Edition standard. That means all fundamental command line parameters are supported per the relevant Java major level specification.
The array of XX variables used by popular JVMs like Oracle HotSpot and IBM J9 should normally be allowed by Zing. In places where semantic meaning is identical, then Zing will honor the values of those XX variables.
If an XX variable has no meaning in Zing (like for instance GC settings for G1 or CMS, which don't exist in Zing) then those variables are silently ignored.