"CMake Error (BoostRoot): CMake support in Boost is experimental [..] Please use b2" - have I been following an entirely wrong path?

Related: https://github.com/boostorg/nowide/issues/202

As my question is more generic and about the CMake configuration of the boost super-project, I wanted to ask it here:

I tried via the following CMake FetchContent call to pull in only nowide (the suggestion to use tools/cmake came from the horrible slop machine, that I really don't want to use but I am desperate enough to see if it produces any useful ideas):
```
include(FetchContent)
FetchContent_Declare(
boost_nowide
GIT_REPOSITORY https://github.com/boostorg/boost.git
GIT_TAG boost-1.73.0
GIT_SUBMODULES libs/nowide;libs/config;libs/smart_ptr;tools/cmake
GIT_SHALLOW TRUE
# OVERRIDE_FIND_PACKAGE
)
message( NOTICE "AFTER FetchContent_Declare" )
FetchContent_MakeAvailable(boost_nowide)
```

This results in a very clear error message:
CMake Error at build/_deps/boost_nowide-src/tools/cmake/include/BoostRoot.cmake:13 (message):
CMake support in Boost is experimental and part of an ongoing development
effort. **It's not ready for use yet**. Please use b2 (Boost.Build) to build
and install Boost.

Since this wasn't pointed out to me in the above linked ticket, I am wondering: Have I managed to trigger an outdated error message that I should disable with
```
set( BOOST_ENABLE_CMAKE ON )
```
or should I really not use CMake with Boost?

If I enable cmake, I get tons of dependency errors and after pulling in a ridiculous amount of libraries:
```
GIT_SUBMODULES libs/core;libs/nowide;libs/config;libs/smart_ptr;libs/assert;libs/static_assert;libs/move;libs/throw_exception;libs/type_traits;tools/cmake
```
and adding them all to the TARGETS to install / export, I get a ton of these errors:
```
CMake Error: install(EXPORT "boost_move-targets" ...) includes target "boost_move" which requires target "boost_assert" that is not in this export set, but in multiple other export sets: lib/cmake/boost_assert-1.73.0/boost_assert-targets.cmake, lib/cmake/mylib/mylibTargets.cmake.
```

In summary:
1) should I abandon the idea of CMake working fine with Boost libraries?
2) if so, is there a minimal example somewhere how to use Boost.Build from a CMake project?