Is there a way to override the default behaviour of climbable blocks?

[Jan5676]

Hey, I had a really simple idea I tried to implement via a new Block Class, the Sliding Pole.

The idea is basically, it acts like a ladder, but increases your downward (sneak) movement by 3 times while slowing you to 1/3 when climbing it.
I set the climbable property to true and fiddled a bit with the OnEntityCollide method. There is a default speed modifier applied (entityAgent.SidedPos.Motion) that only counts when actively walking into the block, however I didnt't know how to adjust the default "sneak" and "jump" functionality when hanging or rather hovering on a ladder. The documentation for this unfortunately wasn't very helpful and I feel like climbing behaviour is implemented at another place I don't know about. This is the code I changed:

public override void OnEntityCollide(IWorldAccessor world, Entity entity, BlockPos pos, BlockFacing facing, Vec3d collideSpeed, bool isImpact)
        {
            if (entity.Properties.CanClimb && entity is EntityAgent)
            {
                EntityAgent entityAgent = entity as EntityAgent;
                if (!new bool?(entityAgent.Controls.Sneak).GetValueOrDefault())
                {
                    //Tried setting to 0 when doing nothing, but gravity pulls me down without "climbable" set to false, but overriden if it IS set to true
                    entityAgent.SidedPos.Motion.Y = 0;
                } else {
                    //Technically works, but I can't really hover
                    entityAgent.SidedPos.Motion.Y = -10.0;
                }
            }
        }

I feel like it's difficult to explain the problem without testing it yourself. Ultimately my question would probably be: How is the climbable property implemented into the game and how could I adjust it accordingly?