could be loose timing chain rubbing up against something? sounds like the problem is during heavy load on the engine, so maybe the chain has stretched and when under heavy load could be hitting somthing? i'm not too familiar with the setup on a 22re. but you did say orbital grinding sound..........timing chain....you can try taking off belts and spin some pulleys, see if you can hear or feel for grinding.

 

High pitched rattling and/or metal on metal sound? If it's not one of the heat shields(Exhaust manifold, catalytic converter), it'll likely be the chain digging into the timing case. Pull the valve cover and see ifthe drivers side guide is still there and intact, but it sounds like you know it's broken already

I'm with the rest, couldn't make much out of the short video. Maybe add a muffler and roll up the window.

 

i concur with the heat shield. i completely forgot about that. my old 96 single cab 4x4 did that same thing. an annoying rattle at a certain rpm range. it was right around cruising speed