I'm using -XstartOnFirstThread argument to solve SWT launch problem in OS X in a Unit test:
-Dosgi.os=linux, -Dosgi.ws=gtk, -Dosgi.arch=x86_64, -XstartOnFirstThread,
-Dosgi.clean=true, -jar ...
21:22:35 [artifact:mvn] Unrecognized option: -XstartOnFirstThread
21:22:35 [artifact:mvn] Error: Could not create the Java Virtual Machine.
21:22:35 [artifact:mvn] Error: A fatal exception has occurred. Program will exit.
There is a misconception on your end. When you run java -X, you get told:
The -X options are non-standard and subject to change without notice.
In other words: anything that starts with -X is highly implementation specific. And of course, that adds the moment of versioning as well.
Meaning: unless you are using the exact same version of Oracle Java on Linux and on Mac, chances are that anything starting with -X might not work the same way.
In other words: most likely your expectation that this works on both platforms is flawed to begin with.