I like the video you guys are talking about. It's well-made and insightful and enjoyable to watch, but it really does paint a pretty rosy picture of perhaps a "best case scenario" of a bengal being introduced to two adult cats. If you think about it, all the guy does is sit back and watch the cats and make commentary on why he really doesn't need to do anything but sit on his behind and let the camera roll
And we never really do see what he did, if anything, to get the kitten and his adult bengal to "play nice", or what the resolution is to that tension. So I'm really not sure how helpful that is to this situation here.
If it were me, I would not keep either cat in a cage. I'm not saying it wrong, just that I wouldn't be able to do it. I guess the one thing that I've read behaviorists say to do, that you haven't mentioned, is to try to create positive associations between the two cats with treats and favorite meals and such. Make it so that each time they meet, something good happens, and is expected to happen.
But it's not easy. I know. I think you just have to keep alternating between brief introduction attempts and cooldown periods until things improve, all the while re-assuring both cats and making sure neither is too upset.