Hello, that is why I recommend you to set enough length of nonce ( > 10000 ) to make it resistant to the brute force attack.
I tried this setting and it still generates my seed pretty fast. As a non-techy user, how would I know if the generated seed is relatively safe from brute force or not? Is there any tool or way for me to check the entropy value?
Check out the "Generated Entropy" area. Copy-pasting those entropy values to
https://iancoleman.io/bip39/ will give you the same mnemonic phrases.
To prevent brute force I think the generation time of 1~5 seconds is a safe measure but I don't think people will brute force them if you are using longer and safer password values.
See
https://www.security.org/how-secure-is-my-password/.