git-blame(1)'s porcelain output does not emit "unblamable" and "ignored" markers

When we want to mark ignored and unblamable lines we can use certain config options(https://git-scm.com/docs/git-blame#Documentation/git-blame.txt---ignore-revltrevgt). It seems to work as expected and mark the lines for the default output format:

git -c blame.markUnblamableLines=true -c blame.markIgnoredLines=true blame README.md --ignore-revs-file .git-blame-ignore-revs

However when we try to do the same with the porcelain format:

git -c blame.markUnblamableLines=true -c blame.markIgnoredLines=true blame README.md --ignore-revs-file .git-blame-ignore-revs -p

It does not mark the lines any differently than without those config options.