DEV’s here’s a simple one.
PLEASE, PLEASE, PLEASE.
Give us Reinforced Options for building materials.
Wooden Wall (4 planks, or 40 wood total) takes 1 C4 charge to blow.
Solid Wooden Wall (10 Planks & 10 Metal Fragments, or 100 wood total) takes 2 charges to blow.
Metal Reinforced Wooden Wall (10 Planks & 10 Low Quality Metal) takes 3 charges to blow.
You could use the same graphics just tint them a different color till you have time to do proper.
Do the same with Metal Walls and such.