Lots of things going on here, very difficult to give any solid feedback without detailed numbers…I recommend you simplify and streamline what you’re doing.
Don’t put anything down. Have every dealer quote you first month payment due at signing to make all quotes apples to apples, then structure it however you want after that. I don’t know what kind of BS your sales guy was trying to explain, but you can structure a lease deal however you want.
Stingers and Optimas and Terrains are all vastly different vehicles. Which one do you want? Always best to shop for the best deal on the car you want, otherwise it becomes very overwhelming. Unless a car is 100% just a point A-B appliance to you, in which case get a 2005 Honda Civic and be done with it.
You need to get actual values for your current Optima instead of just taking the salesman’s word for it. Vroom, Carvana, Carmax, KBB etc. You may have much more positive equity.
You may also want to consider alternatives such as taking over a lease with very few miles remaining or a CPO vehicle if you’re only driving 5.5k miles per year. Leasing loses attractiveness for very low and very high mileage drivers. Yeah, you’re only paying $223 a month, but if you put zero down your lease cost has been $0.486 per mile for your 11k miles - that’s actually not good at all and is very high for a midsize sedan. For reference, my fiancee is driving a 2018 Terrain SLT (FULLY LOADED lol…) for $0.262 per mile, and I didn’t even think it was a ‘great’ deal. SIGNED 2019 GMC Terrain SLT - Michigan $262/mo $262DAS 36/12k