Isn't Kraken the exchange that is famous for creating its own wicks(up or down) on its trading pairs to liquidate positions?, they have a great history of shady behaviors like that and I heard so many people got burnt because of this about a year ago or something, I think the reason behind not showing you the liquidation price is the same reason why they make their own wicks on their charts to liquidate some high leveraged whenever they feel like it.

I definitely would not use Kraken specially for leveraged trading since there are way better and more reputable exchanges for that matter and you won't need to use any formula or a calculator to know when you get liquidated while using them.