Replying to 2019 line chronic ski length. Opinions needed

A well respected NS reviewer suggested the size of 171cm for me concerning the chronic but I would also like to hear your opinions. I'm torn between 171cm or 178. Without a doubt would go longer on a more rockered ski like an on3p but on a more traditional cambered ski I'm not sure of.

Me:
Height - 5'8" adult
Weight - 170 lbs
50/50 AM/park
Learning park, strong skier otherwise
On blends also @171. Feels short on rare occasions.

Note: already have the chronics in 171 unmounted and they measure a couple inches longer then my 171 blends.