I'm not sure that every work of art has to be novel, or that any use of a given technique has to be new, in order for it to be valid or good. That might make it more interesting, or more significant to art historians, but the vast majority of art is about filling in the gaps left by these big strides forward. At the present time, there are lots of artists working in all sorts of historical styles, from petroglyphs, or 18th century academic oil painting, to Impressionism and Expressionism, which are still going strong. Are these modes of art-making out of bounds, according to you? An artist might have a breakthrough and establish a genuinely new way of making art, only to die young, with many of the potential pathways she's opened up remaining to be explored. Is that supposed to be forbidden territory forever afterwards?
As for people extending the aesthetic range of life-casting techniques, you may or may not be delighted by the work of Mark Prent, who is something of a life-casting guru and operates Pink House Studios which sells supplies for doing it (it's certainly not for everyone, and may contain disturbing imagery: http://www.liberallifestyles.com/?p=4646