The solution is surely to mention the escape path from overwing exits in the safety briefing. Slides are mentioned after all. Any passenger seated there needs to be briefed that they would need to open the hatch and when to do so.
My most recent flights in the exit rows have all been with easyJet. In every case the flight attendant was assertive in demanding exit row passengers' attention before briefing them in detail. Obviously everyone says they are happy to stay in the exit row when asked. A warning about how heavy the escape hatch is might put some people off sitting there though. A 20 kg escape hatch is as heavy as the baggage they checked in, but unlike that is not on wheels and may need to be lifted in a sitting position.