I don't believe the 11 minute KT strat is actually possible if playing against players of equal or greater skill. The issue is more so that in games where allies aren't holding more than 50% map control, a KT is all but guaranteed around 18 minute mark from any/all OKW players.
Pretty simple really, if OKW players haven't fielded any armor before 15 minutes, get ready for a KT.
The issue here is that even if you could get enough AT to deal with a KT by 15 min you have given up all initiative. He now has a choice, since you are heavily invested in AT, and he should know that, he can still go KT or he can forgo it and go for more infantry.
The KT arrived later because it allowed both sides to beat on each other for a while, and the advantage it offered was mitigated by arriving later when units were fewer, AT units more numerous, and units had more vet. Now it arrives, even when facing large numbers of AT units, when they have relatively lower amounts of vet, and numerous infantry are scampering around to pick off anything that tries to touch the KT.
I also like the idea of delaying its appearance even if you have trucks unlocked. Possibly a CP limit, or something else. KT's should never be the first tank you see fielded.