[DanCooper]

My settings are currently set to single video per folder but I'm still getting multiple trailers scraped, I got 17 -trailer-trailer files created on my last scrape

With "scraped" do you mean added to the DB as movie? Scraping means you get some information or additional file from a scraper.
 

Is this the sort of thing I'm looking for?

Yes, but you have to add it in a single node like:

xml:
<Setting Section="*EmberAPP" Content="None" Name="NotValidFileContains" DefaultValue="">[^\w\s]\s?trailer|[^\w\s]\s?interview|[^\w\s]\s?featurette|[^\w\s]\s?behindthescenes|[^\w\s]\s?scene|[^\w\s]\s?short|[^\w\s]\s?deleted|[^\w\s]\s?sample</Setting>