Recently I went with a medium chassis instead of the large for my 8.5 Bauer's & for outdoor off rink skating I been using 76 rear & 72mm front with the ice like insert as a result it flexes really well & it feels better then my 01"s.
If I end up playing roller again I will test that combo because we have a small rink around here & agility over top line speed works better for me.
I know the recommended wheel size is 80mm /76mm but 76mm/72mm still works because it's still 4mm difference from fron to rear, reducing the length of the chassis too if your boot size is on the border of the large & medium also allows for more leverage in the rocker, it might work for some skaters.