Peter said:
"In any case given that SPV peers don't contribute back to the network
they should obviously be heavily deprioritized and served only with
whatever resources a node has spare."

This seems very much like a "cut off your nose to spite your face" solution.

SPV peers are INCREDIBLY IMPORTANT to the growth of Bitcoin; much more important than nodes that have the bandwidth and disk I/O capability of being a full node.  Bitcoin will be just fine if there are never more than 10,000 big, beefy, full nodes forming the backbone of the network, but will be NOTHING if we don't support tens of millions of lightweight SPV devices.

Ok, that's an exaggeration, Bitcoin would be just fine in an Electrum model where tens of millions of lightweight devices rely 100% on a full node to operate. But I would prefer the more decentralized, less-trust-required SPV model.

Gavin Andresen