izpack2exe generated executables do not forward arguments properly due to 7-zip bug
It is not possible to pass custom arguments to EXE installers that have been generated with the izpack2exe tool, e.g. to enable silent installation with "-options". The problem is that when you pass additional arguments, they are appended twice to the underlying Java JAR command which leads to a wrong syntax.
E.g. running "myinstaller.exe -options myinstaller.properties" results in an invocation of:
java -jar "install.jar"-options myinstaller.properties -options myinstaller.properties
Note the missing space between "install.jar" and -options which leads to a parsing error.
I did some investigation and it turns out that this is a bug in the 7-Zip self-extractor code. izpack uses 7-Zip 4.64 which is over 12 years old now. The bug has been fixed in 7-Zip 9.34 alpha from 2014.
I suggest to update the 7-Zip distribution used for izpack2exe to the latest version which should fix this issue. At the same time, it's probably a good idea to also update the upx distribution to the latest version, as well.