Paul, remember, our entire system from the MBJ to the x-former is a combo noodle/grounding conductor. (that evil noodle of ours...the root of many problems here....)
The 02' has dictated that all noodles be under dedicated terminations, so this then creates a space problem for which added G-bars is going to be a common fix.
Now i'm wondering about how to obtain a 'floating' G-bar for similar sub-panel dilema's