I played the new ITR beta a bit; with the scavenger mod on scarce. I set up enemy count, increased hunger, and decreased mission reward.
It's fun living off the land but I feel like scarce is just too scarce; since all it really adds is grind. Grinding missions for money is better in vanilla because the reward is anything you can buy. Reward for the grind is much reduced and due to the increased monster count there's very little profit. 

I'll probably leave monster count up for the challenge and then move the quantity of stuff back up to normal; and then probably increase enemy HP to compensate. HP increase I think is a bigger difficulty bump than more enemies because it changes the dynamics of magazines and shot counts, and increases their time to hurt you.