Changing Z-index of just the top 8 pixels of a 16x16 sub-tile in a 16x16 tile-set without messing up the bit-mask.

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:bust_in_silhouette: Asked By 2Dfanatic

Hello, i’m a rookie game dev. i’m currently working on a 2D game which uses random map generation as one of the games core design. Here’s how the game currently looks.
The game

The game uses 16x16 tileset as it’s tilemap . Here’s how the tile-set looks like
The 16x16 tileset
The red bordered subtiles are the tiles that i want their z-index to be changed.
Is it possible to change just the top 8 pixels of the subtile to 1 and the bottom 8 to 0.
I was able to change the top 8 pixel’s z-index to 1 by changing the Subtile Size in the interface on the right. but by doing so messed with my bit mask as well and the image was no longer useful for auto-tile mapping.
Is there any way to change the z-index of just the top 16x8 pixels of a subtile ? Can i use tiles from another tilemap to over-lap over the tiles ? If so, how do i proceed from here ?