That subclause is doing an awful lot of work in your argument.

Well, it's a good thing we've got a century or so of work on the positive manifold/g. I wouldn't want to make anything but one of the best established tests do so much work in my argument!

I'd say that IQ measures part of what most people consider intelligence, but isn't the same as it, and even as a measure of that it isn't an exact measure.

It does not measure all cognitive traits, no, and as a measure it has a pretty precisely known amount of unreliability in it.

Yet I fail to see how either of your sentences are a reply to my comment.