Mod version: TechReborn-1.12.2-2.20.12.937-universal
Digital chest should only be able to store up to 32832 items of one kind.
However, if you ever get to that number just by adding items, it overfills and duplicates all items inside it effectively storing 65450 items ( with half of those being duplicates ). As shown by TheOneProbe and simply being able to extract all 65450 from the digital chest.
Mod version: TechReborn-1.12.2-2.20.12.937-universal