Unless you airut all the way to 200m invention I don't see how it could possibly be a limiting factor. Most you would do invention outside of slayer is to get to the initial 80m xp or w/e for 120 so you don't waste bank trying to get the best combo perks.
I've never done any of the new slayer mobs so I can't comment on exp rates. Only tasks I do now are celestials, shapeshifters, dbs and airuts. Base rates I get for the first 3 are like 360-380k/hr and ~600-700/hr @ airuts.
30-Aug-2016 05:33:54