All the Bundler classes, except for Mac*, have toString definition pointing to their name:

class com.sun.javafx.tools.packager.bundlers.WinAppBundler => Windows Application Bundler
class com.sun.javafx.tools.packager.bundlers.WinExeBundler => Exe Bundler (based on Inno Setup)
class com.sun.javafx.tools.packager.bundlers.WinMsiBundler => MSI Installer
class com.sun.javafx.tools.packager.bundlers.LinuxAppBundler => Lunix Application Image
class com.sun.javafx.tools.packager.bundlers.LinuxDebBundler => DEB Installer
class com.sun.javafx.tools.packager.bundlers.LinuxRPMBundler => RPM Bundle
class com.sun.javafx.tools.packager.bundlers.MacAppBundler => com.sun.javafx.tools.packager.bundlers.MacAppBundler@c667f46
class com.sun.javafx.tools.packager.bundlers.MacDMGBundler => DMG Installer
class com.oracle.bundlers.mac.MacPKGBundler => com.oracle.bundlers.mac.MacPKGBundler@51bd8b5c
class com.oracle.bundlers.mac.MacAppStoreBundler => com.oracle.bundlers.mac.MacAppStoreBundler@7b50df34

Please, do the same thing for Mac bundlers to be consistent.