ORD-LIS didn't weigh anybody's bags, but LIS-ORD did if she thought it looked over. Everyone had to walk by the scales before entering boarding area.

Rollerboards were always weighed basically and if it was over, she would let people reorganize stuff even recommending to drink water if it was in the bag to reduce weight. Was pretty strict on the weight though, but was nice about it generally. I was basically at the 12kg limit for two bags but she waved me through as I had a very small duffle that I simply was carrying with one hand and looks small. Could have put a lot more weight on my backpack, but didn't want to risk it. That'd be my suggestion; avoid roller bags if you can and use a smaller duffle instead. Optically, it looks smaller.