I'm curious: HOW? I always thought those "accelerator" threads were this BS, but this low-fee transaction was actually confirmed by ViaBTC without using CPFP. If that's you, that means you have some "tricks" us mortals don't have, and if that's the case, you don't get nearly enough credit for it. So tell me: how do you do it?
I have been helping since 2017. Unfortunately, the possibilities have been greatly reduced since that time, but some techniques are still available.