i made the first version a year ago, and about 5 months ago i borrowed fiatjaf's cgo code to rework it with a 4x faster pubkey derivation first time it took 5 days
fun fact about PoW mining the more you try the more likely you will get a solution so, you can run it for a day, and then go meh and then another day another day run it... meh and then 3rd day, very likely that you can get a 6 word key