I don't think you still need the backup file since you already have the 24 seed phrases but the purpose of having a backup file from Cold Card Q is an extra backup but 24 seeds should be enough unless you want the backup file because it provides extra protection leaving the 24 phrases unprotected can be easily recover physically.
I don't think you still need the backup file you make things complicated when recovering your wallet.
However, since you said you generated the 24 seed phrase with an extra word(passphrase) if someone stole this backup they can't still able to access your wallet and it should be safe from physical attack and should be enough to keep your wallet protected.
Well, it's up to you how you protect your wallet based on what you said above I don't see anything that can risk your wallet just make sure everything is offline.
I won't disagree with you here, you're likely right on the money. I'm just paranoid. I pretty much run on anxiety, and it's not healthy, hah. Anyways I'll stop over thinking it and just accept that I'm OK with my metal, and paper seed phrase backups and stop over thinking it. Cheers and appreciate your input!