Certain uses of `delta_feature` can cause inconsistent world generation

Hi,

I have a custom biome (Quartz Flats) which uses a `delta_feature` to partially freeze the surface of a lava ocean. This `delta_feature` (quartz_beach.json) is used repeatedly close to sea level in order to accomplish this. However the generation of this feature is not consistent when generating the world multiple times.

The generation should ideally be the same every time.

Steps to Reproduce:
1. Install the datapack incendium v2.5.3-pre.zip

2. Navigate to -276 57 84 in the nether.

3. Look down at the lava and take a screenshot.

4. Delete DIM-1/region, load the area again, and take another screenshot.

5. It will be evident that the generation of the lava ocean is affected by this bug and results in different output both times.