You sprouted 60 seeds, with 35 phenos, treated them all the same and didn't get what you were looking for. Tried again, with the only change being clone vs. seed, and expected different results? Sounds to me like you just kept poppin beans, allowing the pheno to be the only variable of the grow. Did it never occur to you that perhaps KF didn't like some other variable in play throughout your entire experience with KF?
On my first few runs with KF, I had sub-par results plus nanners. While she looked beautifully healthy, turns out I was WAY over-feeding. My keeper maxes out around 300 ppm. Anything over that and quality suffers along with yield, and hermaphroditic tendencies increase 10 fold. She also likes it a couple of degrees warmer than my other regulars. KF is like a smoking hot wife. If she's not happy, you're not getting laid... and she doesn't wan't to tell you that she's not happy. She expects you to just know.
KF isn't paint by numbers. You can't treat her like the last skunk you grew and expect her to strip for you. In Colorado, sub-par bud is recognized as fast if not faster than anywhere else. We have a lot of fire in this state (no pun intended regarding the current wildfire situation). Yet I can barely get Killing Fields into cure before it's gone. I suppose that it's possible that smokers in Colorado simply have no idea what constitutes "potent" weed, but I'm inclined to think that our definition is as reasonable as anyone else's, and KF stacks up. In over 2 years, the only complaint was on flavor, on a batch that I dried way to fast.
So you can't grow a decent Killing Fields, so what. I have friends with cuts that I can't get results out of, but obviously it's not the genetics, because they kill it every time with it.
Greatest truth among "growers" on the inter-webs: When they experience success, it is attributed to skill and cunning of the "grower". When they fail, it's the genetics. Quick to take credit, even quicker to blame anything but themselves. The above post is a prime illustration of this.