I would probably rather gamble in the 5th round of the upcoming draft than trade for Rattler. It's also unlikely they would move him. He's very cheap and he is valuable depth even if he isn't good.
Yeah, I think if people looked at his season of snaps on All 22 they wouldn't have such a rosy view. Not that he is atrocious but he needs a lot of polish in coverage.
PFR shows him has having allowed 16 completions for 321 yards and 2 TD's on 30 targets. This is a 113.3 QB rating on targets. It is the 3rd worst QB Rating allowed in his 7 year NFL career.