Does it work with testing on Mutinynet cashu signet?

Unintentional entropy failure is one thing. Malicious deliberate entropy backdoors are 100% possible in all hardware and software entropy generators. Use handmade entropy. Don’t roll dice - it takes too long, hard to check for balance. Make a big bag of bip 39 words and pull from that after thoroughly shuffling, but even that could have a failure. E.g. the bag was not big enough / words were printed in alphabetical order but didn’t get shuffled well enough. NVK at least five years ago was pretty dismissive about the evil entropy concern.