Alternative to BIP110 suggestion:
Rather than throwing spam blocks away entirely. I want my node to simply wait 1 minute before accepting one as valid. The timing could be variably set and follow the same parameters as your nodes relay policy. If a better block is presented within that 1 minute window, accept that one.
With 25% knots support, this drastically increases the risk of a spam block becoming orphaned. Any ensuing chain reorg happens within 1-2 blocks as the block is ultimately deemed valid.
In the current fee market, a miner needs to mine 625 blocks of spam to make up for a single lost block reward. I think this would be a sufficient incentive for miners to stop mining junk without introducing the possibility of a perpetual chain split.
@mattkratter @GrassFedBitcoin @LukeDashjr @giacomozucco @hodlonaut @dathon_ohm