Can my lug and breaker insert be rotated 180 degrees

I recently posted a question about my panel, Cutler Hammer CH30E, being properly grounded. All ground wires were twisted together and stuck in two lugs screwed into the left side of the panel.

This didn't go over well with Harper. So I got the appropriate grounding bar for the panel. The two pretapped holes for the bar are about 3/4" above the lug /breaker insert and another set 3/4" below the insert. The lower location would be great except none of the grounds will reach. The top location would be behind the 2-2/0 Al wires. It would fit but be close.

Are the panels designed so that the lug/breaker insert can be rotated 180 degrees and the feed come in from the bottom instead of the top. This would free up the top area for the bar and all the ground wires would reach.

There are some improper handle ties from when they built the house. I've got correct ones on order.

UPDATE: Well I think I corrected the problem. I removed the two lugs holding all the ground wire. shown below are the two lugs and the screws that held them to the side of the box.

Here's the panel with the new grounding bar installed. The rep at the electrical supply store ( not Home Depot) assured me I could double ground on the holes, even triple ground, since I got the suggested grounding bar for the cutler Hammer panel. I tried to clean the panel up a bit but was limited because the builders cut the wires so short.

Thanks for your help.