A completely unbalanced thing that cancels out 90% of the spalling. I don’t see how the players opposite can have fun shooting against tanks where you are sure not to one-shot them. In addition, the spall-liner is reserved for a minority of tanks which is the main imbalance.
The solution is not to add a spall-liner to all the mbt’s in the game, otherwise it would be a real zoo.
The most rational solution would be to greatly reduce the spalling absorption values. (For me the easiest thing is to remove the spall-liner even if the devs will never do it :)
I was able to take a screen on a twitch stream where you can observe the impact of an apfsds from a t80b (shot at 90°), this perfectly represents the stupidity of the spall-liner.