Pro tip,

Use reaper pheromones right before birth, claim baby after claim its yours and will not kill you and you can manually feed.

At 12%mat will trough feed.

Also, every step of the reaper can be done without need of the survivor dieing at all.

Hardest part is getting to a prime spot, Rockwell innards I find right under the terminal platform.

Acid bath the queens till the glow red/pink, use a shield of about 5000 metal absorbing the attacks and letting it sniff. I have this setup in my single player, easy peezy. Toughest part is the impregnation part.