Since your compresssion test was good, kinda rules out valve/ring issues. What viscosity oil is in there? Do you have an aftermarket oil press. gauge? If so how many psi @ idle vs cruising?
Okay, this is what I think originally happened when the spark plug/C.O.P. got ejected. When that happened it obviously killed the electrode on the plug, then the COP shorted out either when it hit the fuel rail or when it was bouncing around from all the cylinder air flow coming out the plug hole. When that happened it shorted out the fuel pressure regulator and the fuel pump and the other COP's and the injectors. (how, I don't know) From the repeated cranking of the engine in the attempt to restart it, I got fuel contamination in my oil. What I thought was a rod/main bearing issue seems to be a valvetrain or timing chain issue.
The reason why I think this is I changed the oil and added Lucas OIL treatment and the noise is considerably quieter AND sometime it's gone. I'm thinking it's a semi-collapsed lifter(follower). and the high viscosity oil treatment has helped to pump it back up...