Why doesn't mempool.space discard old unconfirmed #Bitcoin transactions from their mempool unlike others, e.g. Blockstream? It seems that mempool.space keeps them forever without rebroadcasting. It looks like their custom policy.

cc: nostr:npub1uvl7vhclmezvdhqha6eclkksln40rjhgwgsggvew683jf93fr4pq3mq3sd, nostr:npub18d4r6wanxkyrdfjdrjqzj2ukua5cas669ew2g5w7lf4a8te7awzqey6lt3, nostr:npub1hvw02fgyxhl5whxckv4vkglraeamar7r3a54zuztg7v9zw28vukq5a5e8q