I'm not sure I understand how an infinite monkey attack would work against diceware.
Let's assume a word list of 7776 words. All words are lower case alpha. The attacker has pur wordlist. And the attacker knows there are seven words in the passphrase.
That's still 7776^7.
Even if we prune the wordlist ("I'm not using 'zerg' in my phrase", "I rolled 11111, that's not random so I'll roll again") it's still not an attackable space.
Let's assume a word list of 7776 words. All words are lower case alpha. The attacker has pur wordlist. And the attacker knows there are seven words in the passphrase.
That's still 7776^7.
Even if we prune the wordlist ("I'm not using 'zerg' in my phrase", "I rolled 11111, that's not random so I'll roll again") it's still not an attackable space.