Not sure if anyone ever bothered, bt i know it is a common complaint that the metro tunnels of Capital Wasteland is a pain in ass, it is confusing, stink, and fully packed with feral ghouls, etc. Many ppl simply fast travel or never go down one It took me a whole sunday afternoon, about 4 or 5 hrs, to wipe out ALL hostile creatures underneath the wasteland, include a million feral ghouls, reavers, some mirelurks, and rats. Since creatures indoor do not re-spawn, there is nothing left now (at least i think) It doesn't serve any quest purpose, bt psychologically you do feel a sense of great ease since you know the feral ghouls is only history, I may missed few lucky bastards, and there are some ghouls above the ground in Dupont area etc may re-spawn, bt that's really minor. Didn't feel very hard while the character is level 30, plus an indestructible Dogmeat that I used him as a tank lol
Ghoul mask plus one level of Animal Friendship = happy trails underground. I know every manual and guidemaker says ditch Animal Friendship and CHA but i like it just fine. I still get great stats even w/ a 6 CHA. I wouldn't bother w/ 2 levels of AF tho.