Since Vinny's knee is basically shot for the 2019 season this is a great chance for Chris Ballard to get a good look at McLaughling as possibly the Colts starting kicker beyond 2019. Either way, the Colts will move on from Vinatieri no matter what he decides to go beyond 2019. Place him on IR and see what you have from McLaughing. Worst case scenario you sign or draft another Kicker to be your guy.
I don’t care if this team had Tyreek Hill and Deandre Hopkins, Brissett would still stand in the pocket for five seconds and then dump it off to Doyle in the flat. The guy is not the answer, and a bunch of cherry picked stats about his ‘efficiency’ is not going to change that.
He was signed off the street by the Niners. But he was a "non-vested" player, which means he doesn't have enough years of service to reach unrestricted free agency. So whatever team he's on would have his exclusive rights for 2020 and 2021, whether he was claimed on waivers or signed as a free agent. Then he can be a restricted free agent in 2022.
His contract technically expires at the end of the 2019 league year, but the Colts can tender him and effectively extend his rookie contract, one year at a time, until 2023. (And at that point, they could franchise tag him, assuming that provision still exists in the new CBA.)
As a UDFA, the CBA allows him to be signed to a veteran extension after two years of service; for drafted players, it's three years. Until then, his contract is based on the rookie wage scale, which was determined by the CBA.
A recent case study for this is Kenny Moore. He signed with the Patriots as a UDFA in 2017, then was waived at cut down, and the Colts claimed him. After 2018, he had two years of service, so he was eligible to sign a veteran extension, which is what he did in the 2019 offseason. If he had not agreed to an extension, the Colts could have tendered him as an ERFA for 2019, and then as an RFA for 2020.