These definitely were produced. There was one listed on ebay a few months ago. My understanding is that these were mainly available for the Australian market since that seems to be where Ikon Collectables is based in. Also looks like Celebrity Authentics purchased a bunch of them for their...
Propwise, seems like we got more close-up looks of Cap's shield in episode 5 than we got in all the previous MCU films combined. Its like it was its own character in this episode.
There's some type of magnetic trigger on the DCD version. I would think either a magnet or piece of metal close enough to the battery should trip the trigger. There isn't a button to simply keep the light on.
I had a boring job so I spent my time searching the internet all day. Somehow I landed on therpf looking into Star Wars prop and I've been here ever since.