While I agree with your point, and it does feel like it's taking for-freaking-ever to get to the point, I have a competing hypothesis.
Kim was/is a cheating gold-digger. She gets her hooks into Rex, starts the con in earnest, and is moving it along. Gloria starts enabling because it's fun, and isn't too concerned about Kim's behaviour until the engagement. She then needs to ensure Rex is the right man for partner, and she thinks she's been grooming Kim to be the other half of a power couple that will inherit something she worked her whole life to make happen.
Now from a pacing perspective, CBlack needs to establish Kim is a cheater and enjoys it. Then the next beat has to be success for Kim and reinforcing her bad behaviour. Then we need the engagement escalation and the warning from Gloria. The next story beat needs to be whether or not Kim heeds the warning. So Cblack then needs to show those actions, and let the villain (Kim) rise or fall. Obviously we know what choice she makes. If it were rushed and we just saw 2 panels of her saying "fuck it, I'm cheating" it would feel less impactful, in my opinion.
I think we're just reading the weekly drops and itching to see how the resolution plays out. Patreon string-along effect is a real thing too, I just want to give Cblack the benefit of the doubt.
Personally, I would like to see Kim get found out, Rex is unaware that she's been cheating, and Kim is 'sent away' in shame, having lost everything. Rex ends up with the redhead lawyer and they go on to be happy and power-coupling it up. Kim doesn't deserve a happy ending. She's messing with real money and power and is some small time con artist. She shouldn't win.