So im trying to use the global modifier and then specify that scrap needs to be multiplied but i cannot get it to just multiply scrap...

If all you want to do is multiply scrap by 2x use the Simple Loot plugin instead.

For my server, I use Magic Loot to only double the "itemlist" part in the config. In this item list, there are only components and I set these to 2x.  So the amount of scrap given is still 1x but the player is getting 2x the items to scrap so its effectively 2x scrap.