I’d like to do something similar to https://tandem.chat/ (see their video). It has a blur and a custom button on top that says “Watch why teams love Tandem” that opens the video in a modal.
I don’t see a blur, just a faded outer glow. You can achieve this by building your own Lightbox link block with a background video. Just build it like any other div with another div inside it for the button with a hover interaction to scale it slightly and darken the outer glow. Hope that makes sense.