DJI stores are just another vendor. I think all of the US stores are rebranded stores that were former DJI retailers. Such as the one in Costa Mesa was formally Aerial Media Pros, and the same with San Diego, another rebranded store. None of them do warranty repairs, that all goes to DJI. However most of them are DJI approve repair stations for non-warranty work. They do not offer a 30 day exchange policy, not even a 1wk exhange policy from what I'm told. If there's a problem with any DJI hardware you buy from them, it has to be sent to DJI in California (for US sales) for repair or replacement.
On items like this Crystalsky that are hard to get I would order it direct with DJI if you can't wait. I think you would have a better chance to get it earlier, unless you call someone like B&H and they have stock. I think the larger stores get preferential treatment. You might want to call Drone Nerds also, I know DJI likes those guys. I'm waiting for the Cyrstalsky 2000nit version to ship to my local DJI store so I can see it in person, in broad daylight. I want it super bright, not just bright.