I think it would be nice to eliminate "Done" column, which doesn't tell much.
Add "To Be Reviewed" column, where the developer puts cards representing PRs that they would like reviewed.
Keep "In Review" column, but only put in that column PRs that are actually in the process of being reviewed.
I'm trying to use table to track PRs, but the conflation of "want review" with "are being reviewed" makes it
difficult for me.