The Engine now supports Z layering!! There's a few things to note however

Everything still inherits it's position

Just like transforms inherit x,y position, they inherit z position as well. that means that if you move something to Z position 50, and set it's child to Z position 0, then they will both be at Z position 50

Default Z position is 1

This means that everything, by default, will be drawn over it's parent. items with the same parent will fight for the same layer if they overlap ( just like everything on the same Z-layer )

Total Z Layer range is -1000 to 1000

The clipping planes are between -1000 z and 1000 z. However, because Z positions inherit, 11 objects in a chain with Z value of 100 will start to be outside this. so don't go overboard with your z values. Probably best to not go over 100, and even better to generally keep it under 10. Remember, Z-values are floats, just like x and y.

if you need to layer things carefully, default to 0.1 increments (that's the step value in the editor)