Count the tech trash before the sulfur. Each charge wants two, and tech trash cannot be crafted at all: it comes from crates and from electronics you recycle. Unfold it in the calculator and you see scrap and high quality metal, but no bench turns those into tech trash, so the pairs in your box are the number of charges you can make.
The second wall is time. Close to half of a charge's crafting time is gun powder, and powder needs nothing more than a Level 1 bench, so the work splits well across a group.
One player learns explosives, then the charge. Blueprints stay with whoever researched them.
Everyone else crafts powder in their own queue between farming runs.
Tech trash from every crate goes into one box, never into the recycler.
The blueprint holder runs explosives and charges in one sitting at the Level 3 bench.
Do not spend a charge on a wooden door. A satchel opens it for a fraction of the sulfur and comes off a Level 1 bench.
