2016 Camaro 2LT Ongoing Vibration and Knocking After Engine Swap

2016 Camaro 2LT convertible, 109k miles. I still owe 16k. Over the past eight months I have spent about 13k in repairs and still have the same issues.

It started with a random misfire. Multiple coils were replaced, one was installed broken, and shortly after I was told I had zero compression in cylinder three. Chevy quoted 12k for a rebuilt engine.

I had a used engine installed by a local shop for about 4k. After the swap, it went into limp mode due to incorrect fuse box wiring. That was fixed.

Since then:

• Engine mounts replaced

• Power steering system repaired

• Control arms replaced

• Warped rotors replaced (braking shake fixed)

Current problems:

• Persistent knocking from engine bay

• Consistent vibration above 60 mph

• Tensioner was diagnosed and replaced but noise remains

• Multiple alignments and balances show no major issues

My questions:

Has anyone experienced high speed vibration on this generation Camaro?

Could this be drivetrain related after the engine swap?

Is there something commonly overlooked that could cause both vibration and knocking?

Should I be concerned about the used engine itself?

At what point do I cut my losses?

I love the car, but after 13k in repairs I am still stuck with the same symptoms.