Too much timing???

I have no clue; but like the cam-walk idea. Or even the oil-pump drive walking up and down.Or the cam-chain doing a little dance.
That shouldn't be hard to prove tho.
With a cold engine you could index the rotor(or reluctor) to the dist. body,with #6 at TDC-compression. Then check for rotor-shift after the engine is up to temp. I know 4* is gonna be hard to see, so accuracy would be paramount.Why #6? Cuz it's closer to the fender and easier to eyeball, and maybe you don't have to get up on the fender..
'Course this assumes the balancer mark is staying put.
If you do find rotor-shift, you still have to figure out where the source is; cam, chain, or
drive.