I have another idea regarding the plastic bags:
More and more municipalities are now offering organic waste collection and for this you always need the small compostable bags. My suggestion would be to introduce compostable bags instead of plastic bags, especially in the fruit and vegetable section. This would reduce the overall number of bags needed and if they are compostable, all the better.
What does Migros think? :-)

P.S. also fits in well with an M better, for more sustainability.