Found it and set it. Now it seems to not want to play nicely with MO. Which isn't surprising as almost nothing else likes playing nicely with MO, despite how useful it is. I'm gonna take a break before I tear my hair out and try with NMM afterwards. Thanks for your help.
Fallout4 doesn't have scripts.rar, it has Base.zip. As far as I know, they both function the same way... But Merge Plugins is crashing whenever I try to select it... Should I just unzip it and repack it as a .rar file?