Pro has NO hyphenation at all (only one of three hyphens in German are set correctly).
Look, I am not going to argue endlessly about this. This is my last post on this issue. I find this whole argument a bit irritating, to be sincere. There are so many wonderful things in Nisus, I find this a minor glitch, if irritating, I agree with you. The problem is Nisus is based on TextEdit, and Apple didn't bother to set hyphenation rules for other languages than English. I just sent a mail to Apple about it. Not that they'll do a thing about it of course. Word hyphenates fractionally better, but it has so many drawbacks that I don't think it's fair to compare on this rather small issue. And you still have to inspect your hyphenated lines to make sure, neither Word nor Mellel is flawless in this as in other fields.
I just opened a German text (12 pages), went from Courier (font with fixed width, which calls for hyphenation more than others) to Didot, then Times (fonts with variable widths). Result: when I don't click on set hyphenation with fixed fonts, I have to hyphenate manually some eight lines. When I change to Didot, I justify, I don't click on hyphenate, and there the lines are OK, there is NOT ONE LINE that esthetically calls for hyphenation. Then I clicked on Hyphenate, and I had very few words cut in two, of which maybe 30% had to be corrected.
I have yet to use a Word Processor (and I have tried the most outlandish, believe me, including a few which were originally in French) which hyphenates well. Ultimately, you have to go through a text, if really it has to be correctly hyphenated.
as Swiss woman you should know that nearly all German (and Swiss as well) publishers produce books - and I mean academic books like dissertations or "Habilitationsschriften" or other monographs - from a camera-ready copy made by the author himself. All major academic series (e.g. publishers Mohr Siebeck, Tübingen, or Walter de Gruyter, Berlin/New York) are made this way. This is, by the way, the only opportunity to publish a book without or with a low budget.
Even as Swiss woman, I didn't realize this kind of books were typed by their authors who had to give a copy ready for printing. But, as I USE this type of books for research continually, I notice from the two which I have borrowed recently from the library that they are NOT justified, most probably to avoid the problem which so troubles you.
This was my swan song on the matter.