Bought a bull bar used and it did not come with the "packers". It's a bolt and a sleeve that appear to be for side reinforcement on the 2010+ JK's. How important are these? They look easy enough to fabricate but if not needed then won't bother.

I have the bumper mounted but wanted to figure this part out before I put recovery loads on it.

 

Hard to explain how they work. in case of impact the bar will be push back. They help to keep the bar in position so.it does not bend towards the hood. See this video from TJM another Australian manufacturer that uses the same concept you will see how the packers work

Whoever installed the bar was just lazy, I would also check if they installed the crush cans

 

I would say just from the pictures of reduced mounting hardpoints that you will need to be extra careful if you intend to tow or winch from the bar itself. Remember a bar is ony as good as the mounting points and what it is attached to. You could simply get creative and attach it using some thought and adaption methods. Like some HSS square steel spacers with bolts through them to through the chassis for starters. Not everything is bolt on perfect that is why there are welders and steel cutters in the world.