If it were me, I wouldn't worry about it.
- You are checking the oil and it didn't get more than 1 liter low.
- The oil-pressure light never came on
- You don't see any performance changes
So chalk it up to a slightly noisy valve train and hit the road to enjoy yourself.
Car engines make noises. Some make more noises than others, but that doesn't mean
they are about to fail.
