Hi there
right now, the bot picks up orbs and skill gems when they drop. Sometimes it accidentally clicks other times and picks those up also - hence filling up your inventory space.
In order to - currently - maximize your orbs and and skill gem pickups, you can setup your character inventory in a checker-wise order. I have atached an according screenshots.
Since there is only 1 inventory space and not two or three combined, only single space items can be picked up - this also includes jewellry that accidentally gets picked.
By having as many individual orbs as possible with 1 quantity in there, you can stack the other orbs.