Thanks all for the replies. At the moment I'm using the --skip-archive commandline option to get rid of the library.zip. It's not really documented, I found it only in the release notes of a 0.6.x version. Problem is that I now have many libraries in my directory. But I expect to be able to trim a few of these. Is there maybe an option to include only the libraries I provide?
Apparently I'm also using bundle-files=3, but I really don't know what it does... Chris