I hear you, but the very first bullet point in the terms is "To not engage in spam".
That it's not coded in Nostream code.
It will depend on each relay admin and Code of Conduct, I suppose.
Regarding #[3] 's relay, the Terms are on the website: https://eden.nostr.land/invoices
We will see how it's applied as it goes.
Discussion
It is indeed.
And everyone understand the meaning of it.
It's not an absolute definition, true, but it makes no sense to look for it in Nostream code, imo.
We'll see what are the nuances of #[3] 's spam definition as times goes.