it has nothing to do with picking "tough" questions.
If you have a 2 hour stream, and you have over 200 questions we literally go down the line 1 by 1 and answer questions, if a question is asked repeatedly and has been answered already we're not going answer it again.
If a question is off topic to the topic of the stream, you're right, we might skip over it, or we might answer it if we want...
What you might think is a "tough" question, might not be at all, might have been answered in DB articles or the information has been put out time and time again.
I have always been okay with answering ANY question and don't skip questions because it's "tough."
What does that even mean anyways? Like "What is the airspeed of an unladen swallow?" That's a tough question
There is no "devious plan" to hide information or anything... you ask a question, if it gets answered it gets answered, sometimes questions don't.
-Hapa