Comment 4 for bug 1926292

@stephan-shutter: thanks for the bug report, and the practical example of a more interesting preseed file. I've pushed a partial fix for your case - it addresses the unicode portion, but doesn't yet support multiline directives.

@aconte: If the only bug you've run into is the lack of correct unicode handling, then the new version on the edge channel may work for you. Consider running this to try it out:
snap refresh --edge autoinstall-generator