Do Apple Geniuses check if computers are "lost" with iCloud's Find My Mac before performing firmware password resets?
I doubt it, and even if they did, you should not rely on it.

I assume you are concerned about the case where your laptop gets stolen; you want to protect your data. In that regard, the firmware password is utterly useless, the thief could just pull the drive out and access your data anyway.

I suggest you look into something like FileVault 2 instead.