I’ll use it as is. Twenty Characters.
I agree with both points, even just audio would be improvement.
That feature exists and it’s called Quick Channel Select:
This has also been discussed in the past -
via webapp using Firefox First click to enable Picture In Picture 
or from the context menu.
Then click the arrow in the upper right corner 
(the bottom became visible due to the “screen shot” app, otherwise it’s full screen)
If it’s a limitation of the device I accept that, as I stated. It was just a suggestion.
The QCS is a great in-between solution to address what I suggested and having a Previous Channel function.
What you showed is not what I asked.
You completly edited the topic and post, its unclear at this point what question?
Sorry, there was acomment asking about watching a live TV progran with the ability to navigate the grid - as shown.