Nah, what I mean is that there should be a corruption path without a full succumb Axel. When for Lena it's flinging for fun, not something serious with feelings
So far all options start with the sexual relationship (Ian, Robert, Mike, Louise, Holly, Jeremy) that some can evolve into serious / romantic feelings (Ian, Mike, Holly). Nothing suggests really that Lena is falling back in love with Axel during their sex scene. Considering he was retconned in a way that their relationship was toxic even before their breakup (prologue with her crying before she found out about the cheating), it's highly unlikely that she would seriously consider going back to him, especially after he so clearly manipulated her lust for him. Personally, I think this is not about going back to Axel, but about Lena realizing that she still craves to be someone's sub, and Axel understanding that desire which would probably evolve into the Master - Slave relationship but without the everyday boyfriend-girlfriend toxicity that Lena has had enough of with him. She's sick of his jealousy, controlling behavior (outside of bed) and temper tantrums, so yeah, Axel really needs to demonstrate his growth before Lena would realistically trust him to be a potential romantic interest again.
If you specifically meant to keep Axel around as a boy-toy and be equal to him even in bed, then he'd be no different from Robert. Axel's route is engineered to be unbalanced in terms of Lena having unresolved feelings and sexual hunger from all the months without being anybody's sub.