Ultimately, as said earlier speed is the issue here, not armor.
I am such a glutton for punishment but...YOU, and yes I mean you, specifically said that you wanted the KT's armor and speed buffed, so the issue is both in your mind.
Guess what, if you see an American player investing heavily in AT defenses (aka Jacksons) then maybe, and this is gonna sound crazy, you should not invest heavily in a single breakthrough tank. Maybe, you should focus on getting out your own AT units, or just invest in infantry based units and ignore the Jacksons. You already said SU-85's are pretty irrelevant against KT so I won't even bother taking about them.
Alex you don't get an I win button for getting to the KT. You get access, as a bonus, to the only non-doctrinal heavy tank in the game, IF YOU WANT IT. If you don't want it you do not need to purchase it, and in many cases you should use something else. Personally I find Panther + Stuka a better investment most of the time, but would still use KT for some situations.
Please don't respond in this thread if you have nothing new to add, we all know you want to buff armor and speed. You made your point now move one.