I don't like generalizing Kim enjoying grifts as something that makes her a bad person either. Like, generally, grifts have a bad reputation for a good reason, because they prey on good will and when you do that to people who are not harming anyone and they are legitimately hurt by the grift, that's when it becomes unconscionable. So what grifts has Kim participated in?
She and Jimmy scammed Ken Wins into buying them a super expensive dinner under promise he'd be their hedge fund manager. Okay, not good, especially since Ken didn't seem like he was a bad person, just kind of obnoxious.
She helps Jimmy get the better of Chuck in the hearing, which she feels raw about, but given the manipulations Chuck has pulled, I'd say manipulation on their part is fair game. It's not pretty, but I wouldn't say there is a moral issue at stake here.
The big one is the Couchetta scam with Huell, which she is doing both as a favor to Jimmy and because the ADA was treating Huell's case with more harshness than is warranted. In the end, what justice did Huell escape, that he hit a cop with some groceries? Who cares. I'm 100% fine with this con.
Then she scammed that lady with the building blueprints. I don't care about the blueprints being switched out themselves, but this is bad in smaller ways, like the fact that the lady that helped her could have gotten in trouble due to the switcheroo they pulled. This is where it's getting into the nastier aspects of the con in that your preying on the goodwill of well meaning people for no greater purpose than to get a paycheck you don't actually need. Mesa Verde could have just paid the bills to change those plans.
Then she helps with Jimmy's long-con to get back to being a lawyer by making him seem sympathetic. Which....like....I guess isn't good in that it's a bunch of horseshit to make Jimmy look better, but in this case, no one is really being hurt. Unless you count I guess the damage Jimmy is going to do as Saul, but that's another story, because right now Kim still thinks of Jimmy as the good guy who was doing elder law before that fell apart. So, in essence, this is her just helping out a friend and I don't think it's all that immoral.
And this thing with Mesa Verde is her worst one yet because unlike the others, I see it as soothing her ego more than anything. Everett Acker called her out on her insecurities and moral lapses, so she is trying to compensate by giving him what he want and disrupting the plans and wasting time of not just her employer but his hundreds of workers. Like I said before, Mesa Verde isn't doing anything shady here. They just want the goddamn land that they paid for and were as far as possible to the tenants living there. It's not some greater calling, they just want a call center to expand their business, but it's not wrong and it's not like Acker made any kind of appeal of how important his home was to him. He just fucking hates that he has to go and made no bones about that. And since no one, including Kim, gives a fuck about Mr. Acker's right to be there, the only reason any of this is happening is because he managed to touch Kim's raw nerve and now she's making everyone's lives difficult over this overcompensation idea of "doing right". So I'd say this is Kim's worst con because of how petty it is. None of what's happening needs to happen on any moral ground. The big corperation wants a call center, acker wants to stick it to a big corperation, Kim doesn't want to admit that she is, to some extent, a corporate drone, and Jimmy just wants to do Kim a favor.
So one immoral grift to someone really unpleasant, one unpleasant but fair grift to Chuck, one genuinely good grift because Huell's case was bullshit, one mean one to an innocent lady, one mostly good one to Jimmy, her friend and lover, that doesn't realistically harm anyone, and now one petty one over her bruised ego.
I don't think there's any steady progression of Kim becoming a worse person as she grifts more and more. Morally, the grifts are all over the place. It's just this one in particular that's bad, but not like Jimmy defending murderers and drug dealers in BB bad, it's just all really petty for how much time, effort and money is being wasted over this stupid shit.