It’s hard to partially parse the sentence until the very end. If you remove the word “require”, then “mass” seems more likely to be an adjective, along the line

It’s hard to partially parse the sentence until the very end. If you remove the word “require”, then “mass” seems more likely to be an adjective, along the lines of “mass destruction” or “mass casualty”. Inserting a “that” would help. …mass that inaccurate…