I haven’t seen anything to suggest either is happening.
Any limitations in your hardware are more hard facts rather than criticisms.
Now looking at those screenshots the Samsung Smart TV client is extremely old and no longer developed.
Generally any transcoding of 4K is best avoided altogether.
Best achieved by keeping 4K content in its own library and playing only on clients and setups that are capable of direct playing it
I’m sorry but that screenshot of 70-90% CPU usage is NOT an indication that your CPU is handling it well.
Even if you weren’t using virtualisation.
