Replacing/removing overworld grass animation -Emerald

[Auroran]

Hi there, I am trying to replace the default tall grass tile where you encounter wild pokemon in emerald, I've implemented it into the block editor in advance map, however the animation for the old grass tiles still appears on top of the grass whenever the player steps onto the tile.

I have tired following guides to use NSE, but I have since learned that it doesn't work with emerald. Does anyone have any info regarding this or any potential work-arounds?

 

[Auroran]

Does nobody have any insight into this issue?