In OpenCV 4.3.0 built for Android with Tengine support bad Tengine library installation scripts are generated.

1. Configuring for building static OpenCV library, while generating build files it throws:

CMake Error: install(EXPORT "OpenCVModules" ...) includes target "opencv_dnn" which requires target "tengine" that is not in any export set.
CMake Error in CMakeLists.txt:
  export called with target "opencv_dnn" which requires target "tengine" that
  is not in any export set.

and

Error in generation process, project files may be invalid

although, despite error it is possible to successfully build OpenCV.

2. It does not respect installation tree structure while installing statically built OpenCV:
   Instead of installing into directory where all third party library resides (sdk/native/3rdparty/libs/*) it puts it into root installation directory. Also it installs include files in the root directory which are actually not needed and are not installed for other 3rd party libraries.

3. While building shared version of OpenCV it also installs includes and static library into root installation directory. For shared OpenCV configuration it is not needed and all other 3rd party static libraries compiled during building process are omitted from installation.