Sounds like a stupid, pointless exercise. What are you trying to prove? Someone who has stronger gear has a better chance of winning a duel? Of course they do, that's why people upgrade their gear and don't just moan about how everyone else has better gear than you.
Honestly, I don't understand why you haven't quit yet, if upgrades are so game breaking for you. They aren't going anywhere.
Also it seems like you somehow don't know this but this screen is important for duelling:
Now aside from the mouth-diarrhoea you're been spewing out about how unfair it is that people have stronger gear than you because they actually play - absolutely the level cap is going to make duels less balanced - and I don't trust this team to even realise that, never mind actively account for it in the update.