user-1: Let's assume I am a developer of Bitcoin wallet.
If I create a private key without implementing a seed phrase methodology (not using the principles of BIP32 and BIP39), is there at least the slightest chance that by generating a public key and address based on that public key, I will not be able to spend my bitcoins – because the signature doesn't prove that the owner of a private key produced a given message?

user13866: If you properly create the public key and address, there is no chance that the signature created from the private key will fail.
This was true before BIP32 and BIP39. It remains true.

-1: <p>Let's assume I am a developer of Bitcoin wallet.</p>
<p>If I create a <code>private key</code> without implementing a <code>seed phrase</code> methodology (not using the principles of BIP32 and BIP39), is there at least the slightest chance that by generating a <code>public key</code> and <code>address</code> based on that public key, I will not be able to spend my bitcoins – because the <code>signature</code> doesn't prove that the owner of a private key produced a given message?</p>
 13866: <p>If you properly create the public key and address, there is no chance that the signature created from the private key will fail.</p>
<p>This was true before BIP32 and BIP39. It remains true.</p>
