Thx @faizalski for making things work.
We have managed to utilize the passthrough (Tron mode as they called it) on Vive Pro where one of the 4 variations of passthrough actually treats black color as alpha channel. That mode is called Opaque pass-through https://youtu.be/l9w5hAdWZP4
With that mode I am able to make videos with black background transparent. All the colored pixels of the video are visible while I am able to perceive my actual room. It certainly is surreal, meaning you can see your own dick, hands and legs right there with the porn performer. I often would adjust my real body part to match the performers body. I kid you not it is way better feeling of realism than the traditional way.
Some people discover it on Quest passthrough too -> https://www.reddit.com/r/oculus/comments/p713ga/nsfw_adult_videos_on_quest_2_with_stationary/
But the key logic here is just alpha channel elimination. Something like green screen but better. Green screen have too much artifacts and cause color bleeds.
We are looking for ways to introduce the feature in our player to enable you easily make it work. Please let me know if any suggestions
It's expected to work extremely well with black background videos like https://www.sexlikereal.com/studios/pvrstudio
I'd wish there would be some hardcore ones. Something we can work on