This seems like a neat way to make it easier to grow chaeto in a small space and the make it easier to trim/maintain.
I see dramatic (doubling in volume each month or so) growth just lighting chaeto in our refugium. Folks who don't see chaeto growth aren't providing enough light/flow, I'm not sure a structured lattice like this adds much. In terms of trimming, it's easy enough for me to physically pull out half of our chaeto mass once a month or so.