If you have naturally strong legs and naturally weak back then the difference between your squat and your deadlift isn't going to be big. Obviously structural factors come into play as well.
Well... once I get to around 110 kg I feel like I can't progress any further when doing high bar squats for... I don't know exactly, but I think for strength and structural reasons.
So you wholeheartedly think landing after a broad jump with a kettlebell that is a live weight with its own "mind" of where it goes and that you have limited control of in that position is not that risky?
A better exercise would be a overhead kettlebell throw. It will still encompass the triple extension but also do so in a vertical plane. But for safety I'd use a heavy medicine ball.