I think the kind of embedded development you are doing is not the same as I am doing.
Where I work we were looking at CMake and were "forced" to start learning it when we embarked on a pilot project that needed to compile WebKit for several embedded platforms (the kind that can usefully use WebKit to display something). There were at least 3 ways to build WebKit but someone before me chose CMake.
Fast-forward to today, and our main build system is actually a wrapper around buildroot, which can use CMake projects for the packages if desired. We use CMake for one of our Linux kernel modules and for our middleware. We don't use generators, or to be precise we only use the Unix Makefile generator. For the CMake projects we adapt the compilers of our various platforms by using toolchain files, which we write ourselves. Toolchain files are chosen by an option to the initial CMake command and primarily describe the location and preferred settings of the toolchain's tools.
There is a temptation, a very practical temptation, to merge toolchain considerations with the ways targets vary, and handle both subjects with the toolchain file. We have resisted that temptation across over a dozen target platforms. We create platform files separately and we have devised a convention for specifying which one to use.
Our developers all have their own IDE/non-IDE ways of working with the source code and the build system has not asked to integrate in any way with that.
A lot of our developers work primarily within the middleware, and we have a documented way to make that work easy. Others have to cope with buildroot as much as with the build system of the buildroot package they are working on, and that is not refined yet.