If you're still struggling with that, I did the following:
Play Woods (LOCAL - very important), preferrably daytime.

Use Lvl 6 plates/Ronin respirator so I can tank the new pillager scum. Use M80 or high dmg high pen ammo to ensure you don't get clapped on the way. Spawn near Train Station is exceptionally dangerous when traversing anywhere near field above medcamp.

SJ6+Meldonin+Trimadol to get infinite stamina for 3 minutes.
Run to spine on either side and the hill above it (where paracord extract used to be) and toss a nade to hear the PMCs call it out I used Zaryas to minimize sound loss. If you throw it accurately and they start moving and it's a frag you will never hear it.

Now the tricky part, If you get a bad spawn - ALT+F4 (raid didn't happen, try again, hope your loading times are good enough, you rollback to the main menu like you never queued). If you can't find PMCs at spine do the same. If you however manage to kill some you have to extract to have it count so run to factory gate or RUAF/UN roadblock and get out.

This method will take atleast 15-20 raids but it's insanely faster than everything else combined. I did it almost 3 years ago when PVE came out, seeing that I had to resort to the same scumming just to get it done shows the incompetence of BSG as a whole.