But if most nodes are core, they will still relay the spam and they will end up in the confirmed block regardless of you running knots. We'd need knots to outpace all other core nodes for this to be a affective, no?
Discussion
Correct. Still, even at 7% it makes a difference, although hard to quantify. Each additional knots node slows a tiny bit the propagation of spam. To achieve maximum efficiency miners should also use knots policy or construct templates that don’t prioritise arbitrary data. Only Ocean does that for now, as far as I know. If their hashrate grows a few times more than it is now, you can expect a meaningful reduction of spam.
Knots went from 1,5% to 7% in one week, express your vote as you see fit man (I know I have already!)