The strength curve and resistance curve are inversely proportionate. When resistance is low, strength is higher. When resistance is high, strength is lower.
But the highest point of resistance/tension isn’t uniform across all exercises. Tension increases and decreases at certain points during a movement. Knowing this will help you manipulate the resistance curve to create more continuous tension, and thus, more gains.
As a bonus, in the banded curl, the chest pad works as your built-in counterbalance against gravity, so you’re forced to stay strict.