Actually, if you read either of the links provided above, you’ll see that that’s exactly what happens

Yes, that’s definitely sensible and doable

They definitely want your photo. They will photograph / scan your face everytime you fly.

This is already the case.

How does one fill them in without it looking like you have a mess of glue on your fingers

A simple layer of superglue.

Sadly I must sign up. I have managed to avoid it for many years, but it’s a requirement for my work.