This is an idea put forward by a player named Eissar.
He suggested a weapons locker. A building that allowed you to increase the storage capacity of weapons and gear. I can see how this can help since, unlike all other components, weapons and gear do not stack, causing them to take up the most inventory space. I guess the bonus would not be much (maybe a max of 30 extra weapon/gear slots) but it would be a nice thing to have to boost inventory capacity for those who cannot get the book/slot upgrade.
On top of this, he suggested adding new flags (for example, a South African one).