Someone sent dust to my Bitcoin Core wallet, so that's a good moment to test low-fee transactions. In Bitcoin Core, I needed to add this to be able to set a lower transaction fee:

I sent the dust from Bitcoin Core to Electrum (connected to my own node). With default settings, the transaction didn't show up on mempool.space until I used their own Broadcast Transaction (note that my own local node used the default settings up until a few minutes ago).

My transaction paid 0.32 sat/vbyte (35 sats, $0.04) and is now waiting for confirmation in Electrum.
Electrum told me this input is "frozen". I'm not sure if that's the new default for unconfirmed transactions, but I haven't tried to spend unconfirmed inputs for a while. After unfreezing, I could send a transaction to myself. This pays 0.20 sat/vbyte (22 sats, $0.03).

After broadcasting this transaction on Electrum, and without manually adding low-fee nodes to Fulcrum's Bitcoin Core, this transaction showed up on mempool.space! This means it reaches other nodes that accept it on it's own. I like it