Almost anywhere I fly with A3, I see ground staff combing the gate area for roller bags and weighing them and checking in anything that is with too heavy, too large or in excess of allowence. The only place I've never seen it is in the lounge at SKG from where there is direct boarding for most flights. At LHR it's very thorough and usually so at ATH.

I check a bag and only ever have my laptop bag so it doesn't bother me but if you are nervous, check the bag, it won't cost you anything and unlike many airlines, I find A3 generally get priority bags out first and usually quickly.