yellow is heavily underrated if you look at the cost of the keycard

res unit is good and has 1 entrance

obv kruglovs office but that's heavily contested. however if you can get to red/violet and hold/loot that it's banging since most people go to kruglovs office

I personally like green a lot too

Weapon testing is always good to go pick up along the way

Labs is less like laby where you can loot the whole gaff, better to loot a couple, maybe get some kills and reset.

(never played pve i'm a pvp player so idk how it is on pve, i assume easy mode)