in the README there is the following text:

	//.placement(spacing, separation, salt)
	//If all three values match the veins overwrite each other

What do these 3 values do?
Is spacing in the number of blocks or chunks? and is that the spacing between 2 veins of the same kind, or 2 veins of any kind?
I also don't understand what separation does.

I've made my own veins in kubejs, but i couldn't figure this out.

Also, what does the salt parameter do?

It uses the vanilla random_spread structure generation system.

https://minecraft.wiki/w/Structure_set#JSON_format
https://minecraft.wiki/w/Structure_set#random_spread

salt: A number that assists in randomization; see salt (cryptography). Must be a non-negative integer.
spacing: Average distance between two neighboring generation attempts. Value between 0 and 4096 (inclusive).
separation: Minimum distance (in chunks) between two neighboring attempts. Value between 0 and 4096 (inclusive). Has to be strictly smaller than spacing. The maximum distance of two neighboring generation attempts is 2*spacing - separation.

thank you for the quick response!