Separately from "accurate", I would also argue that if the improvement you are proposing is slim or difficult to distinguish from other ongoing ambient improvements - then perhaps you shouldn't try to bring it up as a stand alone project. It's not worth it. "Slim" is not enough impact. You could bring it up as part of a package of other improvements - like those generated day in, day out by a methods or build group. They should be the ones championing small ongoing improvement - and they have an umbrella "do what you can" budget for that.