From a teamgame perspective, I think the KT is okay. Very situational, and I don't believe it needs any tinkering. From my experience the KT is very good bait to get the allied tanks to dive. Mines and raks finish them of and if the KT survives, you can turn the offensive. At Top 200 4v4's allies love to overproduce TD's, giving them not enough indirect fire to deal with raks.
With this perspective, a frontal armor buff for KT makes perfect sense.
To make jacksons (mostly) and other TD to flank and dive.
KT is almost like a panther, but with better AI and HP and worse mobility. Both are used a lot like each other, to set up a clear limit for allied mediums dives and also put some serious drawback on allied TD fron engaging recklessly.
KT frontal armor buff might be also used unitentionally to push through a frontline, therefore i suggested to add a stock hull down for it. Maybe Spios should do it to put some extra difficulty in it. A hull down that will only increase frontal armor would be the best (something like a tank trench)
I also agree that KT popcap is too high, because its a very durable unit but also its costs dont make up for a reliable performance to push through when allied TD are so efficient kiting it and penning it frontally.
No one wants to kamikaze a KT but having one on the field constrains a lot the popcap