Best AFK Method

Hey, I'm new to this game kinda. My question is pretty theoretical, so basically while AFKing which method is better, reaching the highest stage you can or staying in a stage where you Heroes DPS kills the monsters quickly?

I.e My Heroes DPS is 50T shouldnI stay at a stage where the monsters HP is around 50T so I kill a monster per second, or say, a stage where the HP is 350T and it takes more time to kill?

Which method results in the best AFK money?