If your luggage doesn't comply with the rules, you alway take a risk of them wanting to check it. European carriers put a lot more emphasis on this, compared to US domestic carries where some people bring all their worldly possessions on board. Therefore I'd advise against picking up your boarding pass at the counter, where employees of the airline will see your suitcase, and avoid at least one potential weighing and measuring point.
I have been on a LX flight from ZRH to ORD in the past, which was fully booked, where they actually walked around the gate area trying to force pax with larger carry on items (still within the size and weight limits) to gate check their luggage. Took a lot of effort to talk them out of it (O'Hare has the unique feature of a immigration line for carry on only pax, that is often faster than global entry, so I wasn't willing to give up my luggage).