Hey,
I can add items also for the NPC's loot drop?
If not, can you add this feature to the plugin?

+1 

Is it possible to add extra loot to scientist_corpse? I'm unable to get that to work. 

You should google NPC loot plugin , there are free ones out there  :)

Thank you, the free Loot Plus plugin here on uMod has been working and was able to use it to add extra loot to scientists. However it sometimes bugs out and keeps refilling the lootcontainer/corpse with the item. Not sure how to troubleshoot it so have switched to Extra Loot to add the extra loot to crates and things, but not sure how to configure it for npc corpses.