Point out how Midori is being manipulative in any manner and you might have a point.
She's a sad depressed woman reaching out to the woman she used to love, initially acting on old memories because she didn't put any weight into them because of comphet while also seeking out the last time she felt like she belonged. Hell, Midori even seems to acknowledge what she did hurt Maki considering how she's now consistently keeping in contact with her.
I think the problem is that we’re mixing two issues here: Midori looking for support and how she’s getting it.
Midori reaching out to Maki for support should obviously be the Right Thing to do, but the Right Way would also be something like asking Maki “I have problem X, can you help me?” to which Maki could agree and voluntarily provide support in a completely platonic way. (Maki could also refuse, but she’s not that heartless.) Unfortunately, Midori is not yet at a stage where she’s ready to admit that, so instead she tries to get Maki to be nice to her by relying on their previous relationship. She’s giving Maki little bits of affection but always refuses to give her the romantic relationship Maki obviously wants to have, which is hurting Maki a lot, as the most recent chapter showed.
Since Midori’s not playing with open cards here, I can see how her behavior can be described as “manipulative”, but I think the real question here is, is it okay to save yourself at the expense of another? Midori saving herself at the expense of Tazune would get all of my thumbs-up, but Midori saving herself at the expense of Maki, who did her no wrong? Is it okay because Madori is saved more than Maki is hurt? +10 points for Midori and only -5 points for Maki? Is the ratio relevant? -1 point for Maki would be okay but -9 points would not be? Who gets to decide those numbers?
“Saving one person at the expense of another” is a moral dilemma that I find both fascinating and frightening at the same time because while I like to read it, this series made me realize that a couple in my extended family is almost certainly in the early stages of an abusive relationship. orz