I watched the 2 minute "what is brainspotting" video and I think it shares some features with EMDR (which was widely laughed out when it first came out, and now has reasonably solid effectiveness research behind it). I also think the "technique" is basically mindfulness, asking someone to focus on where they feel something in their body (a classic T question that has existed long before any of these somatic based techniques and which does nothing for me). I think asking a client to shift where they look and asking them where they feel something in their body is nothing more than interrupting the perhaps-traumatic automatic reaction. I think the special pointer is a scam, here's something you have to buy to practice "brainspotting".

It could have something to it, especially since IMO it is a type of mindfulness, which is helpful to many people. The specific aspect does seem more like quackery especially in the exaggerated claims of its helpfulness. If I had a T who did it, I would probably be willing to try it if it didn't take up too much time, but I wouldn't seek it out (but neither do I seek out EMDR for myself, which I don't think is quackery). I'm into talk therapy.