Dynamically change CreateLocalRepository option

I have the use case of creating a temporary install that I can then use as a repository to update an existing install. These two installs have unique components that are shipped separately, but are components of the same project.

I can do this step manually but I am trying to script this step for a nicer UX.

My code snippet looks like this:

installer.setValue("TargetDir", "/tmp/TemporaryInstall");
installer.autoRejectMessageBoxes();        
installer.setAutoAcceptLicenses();        
installer.setCreateLocalRepositoryFromBinary(true); //error

Bonus: I also don't seem to be able to switch from a gui instance to a "CommandLineInstance", but I think that's by design?