Help plz need rough idle advice

[Sprog Dog]

Have taken my car to 3 Holden specialist mechanics on the Gold Coast and none of them can solve this rough idle problem. Plz someone help, I’ve done spark plugs, tested injectors, tested coils, cleaned every hole, checked every connector and plug, checked vacuum leaks etc. Changed air filter unit. Throttle body full clean. You name it it’s been done. Is it possible for a timing chain to be off ever so slightly without being picked up? And thus causing a horrible idle?

Check engine compression, get camera and look for gouging if it is down. My car had a rough idle since new. Misfire in cylinder 1 detected at 30,000km. Recently discovered horizontal gouging and now need new engine