Reproduction steps:
1. Download user's project and open "Framework.sln" in Visual Studio
2. Change Win32WinodwHost Path (Unity3DInWPFDemo solution Shell.xaml) to where Buildprofiler.exe exists in the computer
3. Open Task Manager
4. Run the project in the Visual Studio
5. Note the GPU and CPU usage of 'Framework (32 bit)' - CPU 1.5% and GPU 2%
6. Click "Show/Hide" in the CAD Framework

Expected: GPU and CPU usages does not change
Actual: GPU usage rises to 47% and CPU to 26%

Note:
GPU - NVIDIA GeForce GTX 760
CPU - AMD FX(tm)-8350

Why won't fix: hiding Unity window inside embedding WPF app causes VSync to stop working, and therefore Unity starts rendering as quickly as possible. To workaround, disable VSync and manually set target frame rate using https://docs.unity3d.com/ScriptReference/Application-targetFrameRate.html.