Unfortunately, because
FillerBlockType
is an Enum, the only way to do this at the moment (or at least the only one I know) is to create your own class extending
OreFeature
Then override
func_207803_a
copy it and in there, replace
if (p_207803_3_.target.func_214738_b().test(p_207803_1_.getBlockState(blockpos$mutableblockpos))) { ...
with something that checks for end stone, or whatever your ore should spawn in, like this:
if (p_207803_1_.getBlockState(blockpos$mutableblockpos).getBlock() == Blocks.END_STONE) { ...