@Filmstudy hasn't released the OL grades yet on filmstudybaltimore but he has released the podcast where he talks through them with Gordon McGuinness of PFF (also a ravens fan) in tandem with the PFF grades for the game... you can find the podcast here if interested
https://filmstudybaltimore.com/offense-notes-steelers-ravens-week-17/ (i thought it was one of the best episodes of the season)
and Powers graded out with an A while Ehinger languished with a D - notably Powers didnt have any negative pass rushing events in his snaps which is really promising
what's great is that both PFF and Ken were similarly positive about Powers in the game