I got it working a year ago, then my machine died. I've been unable to figure out the interface to transient.
When I view the levels (green and red, with numbers in them), I hit '-i' but see an error 'wrong type argument: (or eieio-object class), nil, obj'.
I'm not sure if that's a bug, or if I have to change the red 7 to a green 1 before I can enable that transient, and I haven't figured out how to do that either.