Why win the lottery twice? This is precisely the problem we are dealing with, this is ONLY for low bit puzzles like 66.
A bot that is sniffing mempool transactions (transactions that have not yet been placed on the blockchain and are stored in volatile memory) gets the public key and in minutes the private key with kangaroo, then initiates a transaction with a commission larger, which has a better chance of obtaining confirmations than the "original" transaction
That is the problem with miners which do not acknowledge that RBF is off for a tx. If tx is with RBF off it should be treated as last and valid only.