I cannot for the life of me figure out what the default weight is if unspecified. The _example.json doesn't mention this, so I don't know what to use for weights relative other materials, for instance the vanilla ores. Only Emerald has a weight specified.

Of the other mod ores, only some are specified, so I can infer that for instance 5 is lower than the default, but I still cannot determine what the default is even looking at the source code.

This really should be explicit somewhere.

Looking closer at _example.json, I notice this line:
"field_76292_a": 10

... Is that supposed to be 'weight'? Half-hearted searching seems to suggest that's the identifier used in some vanilla weighted random code.

While I'm here, there also seems to be 'heightMin' and 'heightMax' values in the example without any explanation, so I think the _example.json needs some attention in general.

So, am I correct to conclude that the default weight is in fact 10? Might be good to specify that in the document for clarity.

You have my sympathies.

Oh ffs, obfuscation leading to JSON serialization writing out that instead of "weight" : 10. Will fix that.

And the height* settings were missing documentation indeed, will add that. Everything else should be fully and correctly documented.

Edit: gah, also some stuff getting removed, I could've sworn that was a straight copy-file. Will fix that, too.