I do not know of any court cases testing LEOSA. However, it could be argued that once you stop, you are no longer in Interstate Commerce. One could run into a District Attorney who decides to make law at your expense. LEOSA, because it is founded on the Fed Gov's Interstate Commerce Supremecy may moot state reciprocity in this matter.
That dog wont hunt...............and there was a court case. It occurred in Sturgis SD. Where as an Off duty Seattle cop was in a bar and confronted with some Hells Angels MC dudes (the cop had in the past worked undercover and was responsible for putting some HAs in jail in the Seattle Area). The confrontation resulted in the Cop shooting one of the MC dudes. The County Prosecutor decided to test the law, saying South Dakota law prohibits the carrying of a firearm in a bar. The LEOSA (HR 218) says 'NOTWITHSTANDING" local laws (meaning regardless of). HR218 Says the officer cannot be intoxicated. In this case the cop, though in a bar was not intoxicated. The judge threw out the case stating he, the officer was protected by HR218.
HR218 was amended this year, making it easier for LE and Retired LE to qualify. Now any Certified LE Firearms instructor in any location can qualify the officer in the officers home dept course of fire. The type of gun is a simple matter, if you carry a auto, qualify with an auto, revolver, a revolver.
I carry a 642 and qualify with it, but just for grins, I also qualify with an auto.
I live in Wyoming, but use the Anchorage PD Qualification (the dept. I retired from). Actually its harder then the course of the local sheriffs office which would work also.
Plus, being my Certification is permanent, though I'm retired I can still qualify other officers/retirees using their course of fire.