> At least those you can turn into covert password fields because they cannot verify them.
Don't do this.
I tried to do this and it turned into a very bad time with their CSRs.
The "security questions" are designed to be answered verbally. They are also designed to be "something you know" that is unlikely to be forgotten, misplaced, or change. Rather than randomized passwords, they're supposed to be something intrinsic to your life that you always remember, especially in a crisis time, and when your scribbled-down credential list is missing.
Based on imitation of a very paranoid security wonk acquaintance, I once set all these security answers to long strings of hexadecimal digits, auto-randomized by KeePass. Big mistake.
They worked for as long as I was setting them, but eventually a CSR, verbally on the phone, began to ask me what they were. The hex strings were nearly impossible to dictate over the voice connection. Also the CSR was kind of pissed about this misuse.
Security questions/answers aren't passwords. Don't subvert them into this use. Your service provider knows what they're doing. Doing this "clever" shit will only hurt yourself, and you're shooting future-you in the foot.