Is there ever any crypto project that allows user passwords to be encrypted into its private key? I've never heard of such I am just curious and thinking about a possibility.
You can use bitaddress.org on an airgapped device. You can use this guide:
How To Run The Bitaddress.org Tool In A Secure Offline TAILS Temporary Live Boot SessionTo generate the encrypted private key while using bitaddress html file
Click on paper wallet, input the randoms characters until it is 100%, click on paper wallet again, check BIP38, input the passphrase and generate. The private key would be encrypted and it stars from 6P.
But I will advice you to just use a seed phrase wallet instead, like electrum. You will run electrum on airgapped device, add passphrase while generating the seed phrase. Adding passphrase is known as salting, not encryption, but it is good as encryption.
You can also use iancoleman.io/bip39/ html file (
https://github.com/iancoleman/bip39/releases/latest/) on an airgapped device, you have to include the passphrase, esle it will only generate normal wallet for you. Or you can use any other reputed seed phrase wallet.