As far as relay policies go, a node's economic weight doesn't matter.

Think about it this way: a node can relay transactions even if it's never been used to verify coins in any particular wallet. A node can refuse to relay transactions even if all it has ever done is download and verify the chain. In fact the "amount" of relaying a node does is the same no matter how it is used. It either relays a transaction or it doesn't.

When people (also including me) talk about economic nodes, they mean that you are using your node to say: "Yes, these coins I accept follow the consensus rules of bitcoin. I will accept them." An economic node with a lot of weight is able to say this about a lot of coins.

The reason relay policy is different is that you and I can have completely different relay policies and still agree on the state of the chain. This is not the case of consensus rules.

A big economic node will still have to accept as valid a block that includes transactions it refused to relay (transactions that it filtered or that it never allowed in it's mempool in the first place).

I suppose the economic node could refuse to accept any block that had transactions it didn't like, but if that was the case, the node would effectively be creating new consensus rules...and it would need to be sure that at least 51% of the hashrate followed the same rules.