You're worried about a fixed gun vehicle being static?
Do you know how much useful a hull downed Elefant is actually or have you used one? Because I have and it's only really useful on extremely choke points and even then it can get artied and flanked.
The KT is also slow so if it's caught out of position with it's slow turret speed as well it's just dead, doesn't matter if hull downed or not.
The only problem would be the Panther because of it's speed, but as the mod team have done with the delay, if it's again caught out of position and cannot retreat it's dead.
So it's a risk and reward thing but I think you're overexaggerating it because you either don't have experience with it or are playing more on the Allied side and think it's going to be OP or something.
You are completely missing the ease of use buffs its getting. Any tank can hull itself down. No support or anything. And they can turn it off rapidly if things get squiffy.
The JP4 would OUTRANGE an, it's already a great TD.
Almost all okw tanks get increased vision with vet, including bonus vision when stationary.
All okw armour has a minimum of 230 armour making them some of the most durable tanks in the game BEFORE adding a damage reduction...
I'm saying there's more to Consider than "hurr durr it'll be cooleo" I know crazy silly things like "faction design" and "will making an already great tank even better upset balance"
Or "what if we combine all things everyone hates about emplacements, make em mobile and let them call in arty"
A hulled down KT with spearhead over watching a VP with a JP4 that could in a few seconds fire at an elefant without risk return fire would be bad design
Especially when you consider that the tank HASN'T given up its mobility-a press of a button and its mobile again, ready to blitz to safety if it needs to...
I'm sayin it's a bad idea shoe honing in abilities that are not considered the repercussions of.
A JP4 could set up shot and outrange a 17lb...
Think man. Think!