Since I have owned the Core, going back to 2015 or so I have only ever used Di3 as I don't do parks etc and two-tone is worthless in a ghost town with its single high tone while fighting the iron and rusted tin.

Mode Di3

Sens 85
ID Mask 10
Vol 20
Brightness 20

A very simple machine as far as settings go. ID Mask at 10 you will hear most everything and it can get pretty busy at times while hunting in a trash/iron-infested sites. I just got used to hearing everything and listening for that "right" sound.

Fors CoRe & Relic
Racer & Racer 2
Whites MXT Pro & M6