However, at this point in time, you'd need very specific and detailed info about which miners would be running such a patched and alternatively-configured node, my guess would be there aren't many of those miners left.
And in the odd chance you do get a 0 fee transaction in his/her node's mempool, and your transaction has very high priority (and the miner still reserves a space in his/her block for high priority transactions), the miner would still need to find a block header whose hash is under the current target (ie solve the block).
Odds are small, very, very, small... But i don't think they're absolute 0.
- How long does it take to get confirmations?
- With today very high dificulty of bitcoin, if someone set up his/her node and do some technical steps to try luck and get 0-fee transactions, I think it sounds very crazy.
[1] Time always make sense. One can send coins and wait for hours or days but too long waiting time does not a comfortable thing to suffer.
According to https://whatthefee.io/, at the current status of bitcoin network, 3 satoshis/ byte is the most comfortable fee (corresponds to acceptable waiting time) to move coins.
I think one can carefully check suggested fees before moving coins but most of time, I move my coins at 1 satoshi/byte and it works smooth.
Beyond that, I know the expiration time of unconfirmed transactions is 72 hours (3 days) [3]. Waiting 3 days, and repeat 0-fee transactions, then wait for luck again sounds very crazy.
[2] If one can be able to set up patched node, then miner's node, I don't see the difference between 0-fee or 1-satoshi/byte transactions for them to spend time (to setup and wait) for luck (too) to get 0-fee transactions.
[3] https://hackernoon.com/holy-cow-i-sent-a-bitcoin-transaction-with-too-low-fees-are-my-coins-lost-forever-7a865e2e45ba