Seems a little conspiratorial to me that magic bots can see a pending Tx, get the pubkey before it posts, crack the privkey and then make a new Tx with a higher fee and front run the first Tx.... Pie in sky if you ask me
It is a very good thing that no one asked you.
Everything you wrote can be executed in less then one second, from start to finish.
Get the pubKey from mempool: instant.
Crack #66 (65 bits privKey): a few hundred ms (with proper precomputed data)
Replace TX: instant.
So it might take you longer to blink then to crack and replace a weak key Tx.
The bot that did it was actually really really slow TBH.