It is not safer. There is no need to use 2048^600 combinations. This is will be problematic for you to save and recover when needed.

It was not generated using iancoleman tool. The maximum number of word it takes is 24 words, as you can see in the picture below

[img with=500]https://i.imgur.com/kBPbNZT.png[/img]
https://iancoleman.io/bip39/

What you might have done, is to use 24 word + 576 passphrase words. This will make your wallet unsafe, risky and you will probably lose your funds when you need to recover it.