lennaert - can you actually describe in detail what they are and how they work? I still don't know any valid reason that the feature is necessary.
When you take the isometric concepts into consideration, there generally is an "offset" differing the height in terrain level pieces.
This same concept is used with the playerbase object / animation object.
Using these together will make (semi) isometric game creation simpler.
Instead of having to do various calculations to determine the offset, you could simply move/lerp the players/playerbase 'off set' toward the offset of the layer the player moves to.
But there are far more 'nice' usages for this ...
Just imagine having 2 layers, big ring at the bottom layer, small ring at the top layer. You can see the big ring through the little rings inside.
Then play with the offset at run time and it could 'fake' a 3d feeling as the off set moves the entire top layer in a circular motion over the bottom layer.
You could have plane shifts, parts of the level move-able.
Or imagine a inner space level, with various layers determining certain 'height' in the galaxy, and as you move your ships, the levels above and below shift gradually.
Or imagine being in an elevator, and the floors below and above gradually pass you by using the offset.
Atm, there are other approaches in which you can all reach the similar results, but it would require more calculations and more events to address everything. In contrast where you could manipulate just one layer.
Some of the above suggestions would assume there is an expression to get the current layer off set.