I don't know how people keep missing that I was talking about Sanchez lol. I'm all for Osuna being a starter, just like I was all for Castro being a starter.
I don't think that play at second is reviewable. It happens a lot where there is a close play at second in a double play but there's nothing that can be done.
The positional adjustment for playing first base is what brings the defense down so much. He could be a plus defender at first but since that's the easiest non-DH position in baseball to play they still get a big negative because it is much easier to play than the others. This is why DH's also get a big negative Def score despite never actually playing defense.