Thanks a lot! 

In short, I failed.

1. This requires installing pip3 on Unix and you'll need to be su

2. If you want to reference npm libraries, you'll need to be su (although technically it's possible to place JS library/libraries code in the XData section(s))

3. The most annoying thing is that most JS libraries are asynchronous and that's a dead end

You have to cast your %CharacterStream to a specific implementation, say, to %GlobalCharacterStream. The latter one implements %GlobalStreamAdaptor, which inherits from %AbstractStream and %Stream.Object. Finally, the %Stream.Object class exposes the CopyFrom method which allows you to copy data from your %Stream.GlobalBinary instance (and vice versa)

Thanks, got it. Then perhaps this setting can somehow be changed programmatically, in the installer code?