If you usually go for stealth sniping, see if you can make melee work. Idk if this counts as an arbitrary rule, but you could always try a different type of build. I guess FROST is next, but I'd welcome suggestions for more mods to my current loadout. What do I do for a challenge now? I don't like arbitrary rules like No VATS or No Power Armor. Zombie walkers causing huge amounts of ferals everywhere, which I managed to survive without a single scratch.

Horizon on Outcast difficulty, in Desolation mode.

I'm 90% done an extremely hardcore survival run.