python-mnemonic VS bitaddress.org

Yes. BIP39 defines a check word to ensure the previous words are correct. You can read the spec here: https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki

ColdCard follows the BIP-39 standard for encoding the wallet's seed as a series of 24 words (a.k.a. "seed menmonic", sometimes called a recovery phrase). If you followed the instructions you were given when initializing it and you've stored your seed mnemonic safely in the real world (not digitally where it can be more easily discovered), you're fine. In the event you lose or damage your ColdCard, you can initialize a new wallet--ANY wallet that follows the BIP-39 standard, which is pretty universal these days--and the wallet will regenerate the same private keysthat your original ColdCard did, in the same order.

... and BIP-39

Look-up "BIP32", "BIP39" and "BIP44", those will point you to documents describing precisely how seed phrases are converted into crypto keys.

i think bip39 is what you want to look up.

Not correct See this: https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki

Here's how I do it: Download the bitaddress.org paper wallet web page html by going to this link and hitting ctrl+shift+s : https://github.com/pointbiz/bitaddress.org/blob/master/bitaddress.org.html

www.bitaddress.org is one of the oldest tools you can use the address format is the old format, but it works just the same. You sent to the public key (you SHARE it like your bank account number). Let people know that's your account, and they'll know your transaction history, so keep that private.)

One of the oldest and best is https://www.bitaddress.org

Is there a Bitcoin hardware wallet which is simply a complete product, which I could presumably keep and use for a decade without update? I'm seriously considering holding most of my coin on a paper wallet generated by https://www.bitaddress.org/ at this point.

Is anyone using https://www.bitaddress.org to create their private key? I was about to use it a few years ago and then I learned about ledger. Now looks like I need to find an alternative again...