How does adding inputs to a Kaspa transaction reduce its storage_mass penalty?

Adding extra inputs to a Kaspa transaction raises the arithmetic mean of their values, which lowers the net storage_mass cost the transaction must pay under KIP-9. The storage_mass formula subtracts a term proportional to input values from the output penalty, so bundling inputs with higher values can offset the fee imposed by small outputs. The catch is that each additional input normally requires a signature from its owner, which means coordinating with multiple parties before the transaction can go through. This coordination burden is exactly the problem KIP-10 is designed to solve with new script opcodes.