It is a DMG with an install4j installer, yes. The installer sets up a couple of file associations, but on macOS doesn't do a lot else. It is a folder installation for ease of access to the uninstaller and an options file. You might be able to just distribute the folder from a completed installation, but I have no expertise in macOS deployment, sorry.
If you are using something like JAMF, then you can install the application on a test machine and use Composer to make the deployable installer package.
@John Mulcahy, thanks for the input. Do you have a list of the commands that the install4j installer can take? And do you know if can be done when no-one is logged in? (lazy ask, I can try the latter).
@sam_adams, thanks. I was hoping to create a AutoPkg recipe to add as a title to our Auto-Update for Jamf service.
It is possible to run the installer unattended, apparently, but I suspect I would need to make some changes to support that - the license needs to be accepted, for example, I think an unattended install would exit there as the default is not to accept.
I tried over SSH with a Mac at the login window using the -q flag, and no joy. (/Volumes/REW/REW\ Installer.app/Contents/MacOS/JavaApplicationStub -q)
Logging in, and trying via terminal with -c -q did work, but prompted for options. (/Volumes/REW/REW\ Installer.app/Contents/MacOS/JavaApplicationStub -c -q).
I guess folks could use expect as a workaround, but not a path I'd recommend.