Well, that was quick. . . .

The Polyscias fruticosa seeds in fact have begun to germinate. Only two so far, and they're so tiny that it's difficult to get a good picture, but this is probably enough to get the general idea:

Sown on 26 September 2015, and I first noticed that something had happened on 18 October, so 22 days from sowing to germination (for the fastest ones). It remains to be seen, of course, whether any others will germinate, and whether I'm competent to keep the seedlings alive long enough to turn into proper plants, but this is at least proof of concept.