Why would a private pilot need to know how to perform a lazy-8 or chandelle? Neither have any practical purpose, other than demonstrating mastery of those maneuvers (yes, they’re supposed to teach control precision and how all 3 axes interact with each other, but I find most pilots don’t get the connection). The only useful commercial maneuver is the steep spiral leading to a power-off 180 landing.
In the helicopter world, the commercial checkride is exactly the same as the private pilot, except to tighter tolerances. If it were up to me, I would change the private/commercial airplane checkride to also be the same, but add in the power-off 180 to both and have the commercial flown to tighter tolerances.