I have been searching and playing alpha videos since I finally got a Quest 3.
The pass-through effect is so great, that I'd say it's almost like the best thing ever happened to VR videos.
At the same time, your experience might be quite different, because of the wrong 6DOF settings. So I want to share my setting here.
Basically if I play a video with alpha , I will turn off the "Override 6DOF settings", because it's not the optimal. When my head moves, the image also moves, which defeat the purpose of 6DOF.
Then I will go to the 6DOF setting and turn it on. The "6DOF speed" setting there is very important. If you set it to 0, the image will move around with your head moving. If you set it to 2, the image might get distorted too much.
My best setting so far is "0.72". There is still some slight movements with the image, but it's quite solid. I feel like the image is right in front of me and it doesn't go left or right.
At that point, I will be able to get better immersive experience by "dragging" the whole screen to the place I like. I will see that the image is like being right there alive.
So what is your setting for 6DOF with Alpha videos ? Did you have similar experience?