Are there any plugins/commands that can do that?
I would like to give players more nodes. They search a lot and don't find enough.

What about Map Salt?
Does this change something about it?

You can use plugin CustomResourceSpawns or you type in start bat these settings and higher the number.
spawn.min_rate 1
spawn.max_rate 1
spawn.min_density 1
spawn.max_density 1

But be careful. This increase also animals, trees ... not only ore.

Thank you.
So, there is no such command for only nodes?

Not that i know of. Another method is open your map file in rustedit and edit the topology. Here´s a tutorial https://www.corrosionhour.com/adding-nodes-to-custom-rust-maps/

Thank you.