If you extend your seed phrase with a passphrase, you are not expected to commit the passphrase to memory, just the way you are not going to commit your seed phrase to memory, your passphrase should be backed up on paper, but in a different place from your seed phrase. Extending your seed phrase with a passphrase is a good layer of security and it can also be used for plausible deniability, so i recommend.
Good point! Storing the recovery seed in safe places and knowing where it's at the time of recovery, assuming you didn't just keep it at home, is a challenging process, as someone with knowledge of cryptocurrencies could find it and try to drain your wallet...
Hence the importance of extending the recovery seed to a custom word/passphrase and using it as a 2° factor.
However, some care must be taken, such as not storing the recovery seed and the personalized password in the same place together, but it is challenging, as it requires your creativity to know how to store this data without anyone with knowledge of cryptocurrency finding it and without you losing it. or forget where you stored them.