Explicitly specify that the rubble placed on death is decaying.
This breaks quite a few mods, then again the fix is running sed.
Rough command to update things find binaries/data/mods/*/simulation/templates -name '*.xml' | sed -i 's,<SpawnEntityOnDeath>rubble/,<SpawnEntityOnDeath>decay|rubble/,'. This should be correct for everything but fields, which at least in the public mod use a different delay.