I like the idea of the prequels-as-flashback (and actually wrote about it on my site before “Machete Order” was a thing), but I’ve never tried it personally. For a new viewer, I would always go release order, with the prequels as a last resort, so my list would be:
SW, ESB, RotJ, TFA, R1, TPM, AotC, RotS
But probably end up being:
SW, ESB, RotJ, TFA, R1, SW