> it's also valid that having to re-download transactions that were already filtered out is an impact Nodes don't just "download" transactions, they also "upload" them to their peers, again and again as long as they are in the mempool and they have peers to upload them to. Core folks love to focus on the fact that if you eject spam from your mempool and it gets into a block, you will redownload it. But they neglect that if you *keep* spam in your mempool, you will repeatedly upload it to your peers. So removing it actually saves you on bandwidth. You may have to download it twice, but you have to upload it 0 times instead of 7 or so.

It is. Which is why having it user configurable was the sensible way to handle it. Core is like iBitcoin.