Savage Spirits page 46. The Mk. III Modular Backpack, and the Pannier Modular Cargo Handling System. Both have similar wording, and I want to make sure I understand it right.

The "modular backpack increases a wearer's encumbrance threshold by 2, plus an additional 1 point of encumbrance threshold for each accessory pouch added to the backpack (to a maximum increase of 6)."

My first impression is that this means a maximum of 4 accessory pouches, yet it says in the flavor text "The Mk. III is also equipped with a system of hooks and fasteners that allows up to six smaller pouches to be attached". Does this mean 6 possible accessory pouches?

Similarly, the Pannier has 2 cargo containers so "increases the creature's encumbrance threshold by 6, plus an additional 3 points of encumbrance threshold for each additional cargo container added to the system (to a maximum increase of 12)." Does this mean two more containers, or four?

I believe the maximum increase for the backpack is +6 via pouches, so the max total is actually 8, same for the Pannier to a total encumbrance of 18.

The wording indicates a max increase to encumbrance of 6 for the Mk. III Modular Backpack, which includes both the base pack's +2 and the individual pouches' +1 each. In this system, RAW says the mechanics trump the fluff, but I don't see any issues in allowing you to add a pair of the Military Belt Pouches ( Dangerous Covenants pg. 59) that can each hold a pair of Encumbrance 0 items (like Stimpacks) with those "extra 2 pouches". Alternatively, you could certainly add 6 "upgrade" pouches, but you would only gain encumbrance boosts for 4 of them.

By the same token, the maximum increase of 12 for the Pannier is pretty clear, so that would be 6 for the base container plus 3 each for 2 additional containers. You can add more, but you don't get the benefit of added encumbrance for them.

Comparing to the Modular pack in Enter the Unknown the "to a maximum increase" means the maximum that you may increase the Enc bonus by, not the max increase to. So the pack can carry 6 additional pouches (to a total of +8 enc) and the pannier likewise tops out at 18.

I'll have to let my players know that I've been playing it wrong, then. Thanks!