Very low fps with biome specific grid colormap to grass_block

[s-k-y-l-i]

Hi!

This is my code:
{
"format": "grid",
"source": "./white.png",
"blocks": ["grass_block"],
"grid": [
{
"biomes": [ "terralith:birch_taiga", "terralith:moonlight_walley", "terralith:lavender_valley", "terralith:lavender_forest", "terralith:sakura_grove", "terralith:sakura_valley", "terralith:orchid_swamp", "terralith:shield", "terralith:yellowstone", "terralith:moonlight_valley", "terralith:moonlight_grove" ],
"column": 0
}
]
}

And it makes a huge fps drop to 3-4 FPS.
If i change the blocks to "grass" for example, it doesn't lag, but the grass block is.

I have sodium.