Start with your local state patrol
Depending on who you talk to here in Ohio bumpers have to be full width IF it came from the factory with a full width bumper.
As far as crumple zones etc , ARB is built to those standards and in fact also has some crumple zones built into the frameworks to work with the Jeeps.
As far as others go its wide open, I am sure you've seen all kinds on the road up there just like here
04 Liberty, Kilimanjaro Edition, Rock Lizard RockRails/Roof Rack/Front-Rear bumper,32 inch Goodyear Duratracs,Moabs,4.10s/ 4.25 inch JBA Coilover lift /other goodies