He's 31 now (likely 32 next offseason) so I don't really see the point in seeing if he's really an NFL starting QB. I'd just rather either go with Carr meaning you are trying to win the Division this year or go with an upside guy like Rattler, Fields, Malik Willis, McKee, etc. And, as you know, my preference is to go with a young guy to find out if you need to draft a QB high in 2026. To me, someone like Rush means you are going to draft a QB high in 2026 because you know he isn't the long term answer and you don't know if Rattler or another young guy is. And I hate the idea of being forced to pick a QB high in 2026 since you just never know if any of the QBs will be worth a high pick, and if they are, you don't know if you will be in range to pick them.
I guess if you bring Rush in as a veteran backup to mentor the young guys I would get it. But, it would have to be a really cheap deal.