@Ho3n3r I am not pushing for anything (don't even understand why would I), neither have I said Steam fps counter is better (please quote if you think I did, or even that I am apparently "pretty adamant about it"). You stated that you do not want to use the Steam fps counter because you don't want to run 3rd party apps you don't need , which surprised me, because that suggested you're not running Steam (which would certainly be quite weird, given that ACC is a Steam game). So I am simply pointing out to you that despite what you seem to think, you are in fact still running it, regardless of whether you have the overlay enabled or not, so logically, you might as well use its universal fps counter that works in every game without the need of looking for native in-game solutions for each.
But I have to say I would think the scenario you've described, as in running a few tests with the FPS counter and then disabling it again makes the Steam counter much more accessible and user friendly, as you simply turn it on or off with one (well, two) clicks at any moment (and certainly without having to restart the game), instead of having to edit some file. But granted, you have to be using the overlay to be able to turn it on or off like this, which you apparently are not.