When picking berries on a long mining trip, I noticed that I wasn't getting any more berries from picking. Each of my inventory slots was taken but i had partial slots filled with the currants I was trying to pick, so I honestly thought it was a bug and resigned myself to tossing an item to leave a slot open. I was surprised when the new berries ended up in the open slot rather than stacking with my existing berries, and so I discovered the game's tendency to avoid stacking items with different enough spoilage levels. I actually like this mechanic quite a bit, but it has proved to be very annoying multiple times and so I propose a solution: add an option for it! A few, actually. I'd like to see three (maybe four) different behaviors available to choose from:
1. Always keep separate: Exactly what we have now, could be nice to enable in situations where you know you're about to consume items which are about to spoil.
2. Always stack: Pretty self-explanatory, would simply disable the mechanic and always prioritize compactness.
3a. Stack when inventory full (new default): Keep separate, unless no slot is available, in which case the new item would be stacked.
3b. BONUS OPTION: Aggressively stack when inventory full: Same as above, except the check is run whenever any item tries to be added, and existing stacks in the inventory can be merged to make room. Example: you have two stacks of five currants in inventory, and game tries to add a stick to inventory and fails. Game notices that item addition was blocked, merges the currants into a single stack of ten, and adds the stick to the newly opened slot. Would be significantly more difficult to implement and isn't necessary at all but I thought I'd throw the suggestion in.