Decide when Backpack capacity is the right Mine a Mountain upgrade without relying on unverified tier values.
Backpack is a sell-loop upgrade. It is strongest when the route still has safe mining time left but the bag forces you back early.
Your bag fills while you can still safely climb and mine. In that case, Backpack directly reduces wasted return trips.
You leave because the upper route is too cold. Backpack space will not fix that run; check Warmth before adding capacity.
You reach crystals but break them too slowly. Backpack helps later, but Pickaxe pressure is the current bottleneck.
When the bag fills before the route is otherwise unsafe or too slow. That is the clearest Backpack signal.
No. The public evidence confirms the Backpack role, not a reliable current tier table.
Check whether the last failed run was stopped by capacity, cold, or mining speed, then use the planner if the blocker is unclear.
Return to the guide hub.
Use this when cold ends the climb.
Connect capacity to the crystal sell loop.
Use the climb, mine, sell, upgrade cycle before adding capacity.
Compare Backpack, Warmth, and Pickaxe qualitatively.
Review role-first upgrade priorities.
Check evidence boundaries and correction policy.
