In real life, the gravity of this planet is 8.87m/s²

In the mod, it is 61% of overworld's, or 5.98m/s² if you count. (9,807*100/61)

And so I think you should be able to only jump like 1.5 blocks on Venus instead of 2 or 3.

Let me know what do you think, if you'd like to change it or not.