Auto-destructivism tamed?

Gustav Metzger, the father of auto-destructive art, is one of the highlighted artists at dOCUMENTA (13).  His early sketches and steel paintings are extensively displayed.  With his drawings hidden inside glass display cases, viewable only when the cloth cover is lifted, even the fierceness of the fire of auto-destruction seems to have been contained.

Metzger at documenta-Halle, Kassel 2012: