I have a small app that when specifying the Installer classic theme results in an exe or msi installer size of 6 to 7 MB. If I select the App Installer theme it balloons out to over 30MB. If I change back to a Classic theme the exe file does not reduce in size.
The App Installer theme adds significant code to the install file which remains even when switching to another theme.
I am on v21.8.2.