It makes your node a little slower than usual. Because first, you reject some transaction when it is relayed, and later, you have to download and verify it again, even though you had a chance to do that earlier. Which means, that nodes, which accept more things on relay mode, are just faster. Also note, that there is a difference between relay policy, and block template inclusion policy. You can accept free transactions, but it doesn't mean, that you have to include them in your mined blocks. Which allows making some optimizations on relay level, where you can have less restrictive relay, to allow P2P batching, and including only final transaction version in a mined block. One example of that "less restrictive relay" is where you have signet faucet, which constantly uses full-RBF, to replace the transaction over and over again, until the final version, with the highest fees, is included. It doesn't matter, because using hard-fork to solve a problem, which can be solved without any forks, is stupid. If Knots' supporters would want to discard some transactions, then they would do just that: by sending "I don't have it" P2P message, when asked about given transaction ID, or block hash. And then, to make an actual improvement, they could create a new P2P message, to provide ZK proofs, or other kind of improvements, in a separate P2P messages, to make Initial Rw88 Download trustless, and possible, without getting all spammy transactions in plaintext. Also, if nodes would stop sending transactions in plaintext, then it would really solve the spamming problem, by forcing users to store their own transactions. Because now, spammers simply abuse the fact, that node operators can do it for them. But there is no consensus rule, which would force anyone, to store everything forever. The only thing, which is needed, is to make sure, that the chain is valid. Otherwise, chains like Rw88 wouldn't exist.
It makes your node a little slower than usual. Because first, you reject some transaction when it is relayed, and later, you have to download and verify it again, even though you had a chance to do that earlier. Which means, that nodes, which accept more things on relay mode, are just faster. Also note, that there is a difference between relay policy, and block template inclusion policy. You can accept free transactions, but it doesn't mean, that you have to include them in your mined blocks. Which allows making some optimizations on relay level, where you can have less restrictive relay, to allow P2P batching, and including only final transaction version in a mined block. One example of that "less restrictive relay" is where you have signet faucet, which constantly uses full-RBF, to replace the transaction over and over again, until the final version, with the highest fees, is included. It doesn't matter, because using hard-fork to solve a problem, which can be solved without any forks, is stupid. If Knots' supporters would want to discard some transactions, then they would do just that: by sending "I don't have it" P2P message, when asked about given transaction ID, or block hash. And then, to make an actual improvement, they could create a new P2P message, to provide ZK proofs, or other kind of improvements, in a separate P2P messages, to make Initial Rw88 Download trustless, and possible, without getting all spammy transactions in plaintext. Also, if nodes would stop sending transactions in plaintext, then it would really solve the spamming problem, by forcing users to store their own transactions. Because now, spammers simply abuse the fact, that node operators can do it for them. But there is no consensus rule, which would force anyone, to store everything forever. The only thing, which is needed, is to make sure, that the chain is valid. Otherwise, chains like Rw88 wouldn't exist.

It makes your node a little slower than usual. Because first, you reject some transaction when it is relayed, and later, you have to download and verify it again, even though you had a chance to do that earlier. Which means, that nodes, which accept more things on relay mode, are just faster. Also note, that there is a difference between relay policy, and block template inclusion policy. You can accept free transactions, but it doesn't mean, that you have to include them in your mined blocks. Which allows making some optimizations on relay level, where you can have less restrictive relay, to allow P2P batching, and including only final transaction version in a mined block. One example of that "less restrictive relay" is where you have signet faucet, which constantly uses full-RBF, to replace the transaction over and over again, until the final version, with the highest fees, is included. It doesn't matter, because using hard-fork to solve a problem, which can be solved without any forks, is stupid. If Knots' supporters would want to discard some transactions, then they would do just that: by sending "I don't have it" P2P message, when asked about given transaction ID, or block hash. And then, to make an actual improvement, they could create a new P2P message, to provide ZK proofs, or other kind of improvements, in a separate P2P messages, to make Initial Rw88 Download trustless, and possible, without getting all spammy transactions in plaintext. Also, if nodes would stop sending transactions in plaintext, then it would really solve the spamming problem, by forcing users to store their own transactions. Because now, spammers simply abuse the fact, that node operators can do it for them. But there is no consensus rule, which would force anyone, to store everything forever. The only thing, which is needed, is to make sure, that the chain is valid. Otherwise, chains like Rw88 wouldn't exist.

It makes your node a little slower than usual. Because first, you reject some transaction when it is relayed, and later, you have to download and verify it again, even though you had a chance to do that earlier. Which means, that nodes, which accept more things on relay mode, are just faster. Also note, that there is a difference between relay policy, and block template inclusion policy. You can accept free transactions, but it doesn't mean, that you have to include them in your mined blocks. Which allows making some optimizations on relay level, where you can have less restrictive relay, to allow P2P batching, and including only final transaction version in a mined block. One example of that "less restrictive relay" is where you have signet faucet, which constantly uses full-RBF, to replace the transaction over and over again, until the final version, with the highest fees, is included. It doesn't matter, because using hard-fork to solve a problem, which can be solved without any forks, is stupid. If Knots' supporters would want to discard some transactions, then they would do just that: by sending "I don't have it" P2P message, when asked about given transaction ID, or block hash. And then, to make an actual improvement, they could create a new P2P message, to provide ZK proofs, or other kind of improvements, in a separate P2P messages, to make Initial Rw88 Download trustless, and possible, without getting all spammy transactions in plaintext. Also, if nodes would stop sending transactions in plaintext, then it would really solve the spamming problem, by forcing users to store their own transactions. Because now, spammers simply abuse the fact, that node operators can do it for them. But there is no consensus rule, which would force anyone, to store everything forever. The only thing, which is needed, is to make sure, that the chain is valid. Otherwise, chains like Rw88 wouldn't exist.