Please move guild renown to the top of the treasure list, or make "Loot All" start from the bottom of the treasure list.
The reason is quite simple: when short on inventory, it requires unnecessary deletion of an item to pick up from a chest. For example, say your backpack has one empty square of inventory, and the chest contains two items that don't go into bags, say a quarterstaff and a heroic deeds. If you pick up the heroic deeds first, then it goes into the empty square and disappears, adding to your guild renown, and you are then free to pick up the quarterstaff. However, if you pick up the quarterstaff first, then you must now delete an item from your inventory before you are able to pick up the heroic deeds. Unfortunately, pressing "Loot All" will always pick up the quarterstaff first, preventing you from picking up the heroic deeds.
Regardless of how many empty squares in your backpack you try to maintain, and thus how many quests you can complete before going back to town, this issue is almost always encountered, since typically you find out you are full for the first time when pressing "Loot All". At least that is my experience.