HP and weight values have been halved have for parts of the duct that have less armour visible. 3x3 has a 1 block adjustment, 5x5 has a 5 block adjustment, 7x7 has a 24 block adjustment.
Fixes
Ducts
Heavy armour HP values were wrong, these were corrected.
Multiplayer
Fixed issue with infinite materials in multiplayer designer overflowing to -materials on the client