No, do not reintroduce hull break. It was awful and literally made more problems than solved problems.
Vehicles with poor protection survive AP impacts because the AP lacks the capability to impart its energy into the light armor, that’s literally realism. If you know you’re likely to face trucks and light armor in your BR zone, bring HE as a first shot. This is especially true for the Jagdtiger, where the HE is very effective, having HE content that is more than capable of killing literally everything on the battlefield frontally. 3.7 kg of TNT will absolutely demolish literally anything, provided you know how to aim.
I’ve literally gone played the IS-4 exclusively firing HE in the past and it is surprisingly effective. The Jagdtiger has around the same HE content for its ammo.
That’s not realistic in the slightest. Your video shows what amounts to the most optimistic extreme edge case where a full caliber “AP” shell transfers significant KE to the target, but you failed to note that the 105mm round was not actual 105mm ammo from history.
That’s a cast pot steel round, that is both especially soft, heavy and slow to not put much strain on the gun and pressure bearing parts. Actual 105mm L7 KE ammo would fly into the aluminum engine block and fly right out the other side. The cast pot steel ammo is equivalent to using a hollow point bullet on a soap bubble. Not at all representative of 105mm APDS or even 105mm AP/APHE. Note that a majority of catastrophic damage images from the web are due to one of three factors; fire, high explosive or multiple shots.
Load HE then. You can and most certainly will oneshot many vehicles of any weight class with large guns. I load HE or HEAT whenever I need to deal with something without armor, it’s second nature for me now. If you can’t reload safely, then you make the best of the bad position you put yourself into and fire into the “hardest” part of the light vehicle and hope your HE content carries you. It works quite consistently.
No, that’s nowhere near reasonable. Hull break was a punishment for light vehicles because most players were too apathetic to load the correct ammo. Unless it’s applied globally (see LOSAT kill mechanism IRL), it will always remain a punishment for light vehicles. Overpressure and correctly functioning additional modules are fine for now.
If anything, were you to actually suggest a reasonable “hull break” it’d be made exclusive to ammo with high explosive content (and certain edge cases such as LOSAT) as KE ammo will overpenetrate and fail to deal significant damage even when hitting “hard” modules of vehicles IRL. HE makes the entire structure of things warp and fail, KE will sail through one side and right out the other, even if there’s a lump of aluminum in between.