Submit script only (3dsMax)

Not quite.
You still need to provide a scene file as argument to the submission, but it could be a dummy empty file. You can easily create one using the MAXScript function call

SaveNodes #() "c:/temp/emptyfile.max"

Then you have to provide the .MS file as second auxiliary file argument after the MAX scene file in the deadlineCommand call.
In the job submission’s plugin info file, you must set the property

MAXScriptJob=1

to inform the Deadline Slave not to render the scene but to run the included MAXScript.
You can also set

UseSlaveMode=0

to force 3ds Max to run in Workstation mode, since MAXScript has a long list of limitations when executing in Slave mode without the GUI. However, a 3ds Max license would be required by the render node in this case.