Steps to reproduce:

1. Open attached project
2. Open 'Isaac_SubstanceTest' scene
3. Make sure 'sphere' material has Load Behaviour set to 'Bake and discard Substance'
4. Build and run the scene in development mode with profiler connected
5. When porfiler is opened, click on the Memory tab and select 'Detailed' view
6. Click 'Take Sample: WindowsPlayer'
7. Expand 'Assets', notice the SubstanceArchive is still present with the 'sphere' material in it

Expected behaviour would be that the material gets discarded, as it is set to 'Bake and discard Substance' on load.