Given that it is a mini key. Is it possible to use 256 bits ?
No, because the newer standard is still only 30 base58 characters and the first character is always "
S";
Even if you managed to device a way to use a complete 256bit entropy to generate it,
the security wont still be 2^256 since an attacker could just go for the mini private key itself, and not the entropy.
It was a site walletgenerator.net
Oh, so it's not entirely related to mini private keys but about bad entropy.
Yes. The site has bad entropy or back door .. but we can’t trust anyone anymore.
Hence asking for feedback for mini keys.