There was a story in "I Learnt About Flying From That" concerning a Cessna 152 of all aircraft in a spin with imbalanced fuel. The (very experienced) instructor had to reset pro-spin controls and snap in full anti-spin control to finally recover - in by far the easiest aircraft to recover I have ever spun! Can affect all, and at least in aircraft with selectable fuel tanks there is some encouragement to fuel-balance awareness.