>In addition changing a header file can at times trigger a lengthy build.

Well yeah, but that's true for doing it by hand too. If it's that slow, you won't have automatic builds on anyway, and you can usually cancel it if you need the CPU for some other reason (in which case, again, why do you have automatic builds on).

And even if it were only a 90% thing, that's a 90% savings. I mean, literally, if you change the name alone, change the header name. You get immediate notification that other locations might need changing if/when the build fails. Similarly for argument order / name (type will probably cause build failures).

But all those build failures would happen anyway if you changed it by hand, so it's not any different, just faster. Isn't faster the goal here?

In fact, I think the Visual Studio team once said that it's so excruciatingly hard to build C++ refactorings that won't destroy code in unhappy circumstances that they won't bother shipping such things.