This is something the reef tank community has been using for years, in fact there are whole businesses built around the practice of fragging and selling corals... to the point that there is already equipment made for this purpose.

From "frag tanks" built wide, long, and shallow to allow light to have an easier time reaching the corals, to "frag plugs" made from ceramics that allow people to glue coral frags to to slot into existing rock, egg crate, etc.

I think maybe the accidental discovery was that the researcher found that this very common procedure to cultivating aquarium corals ended up also promoting the growth speed too.