It has been hot; he has been naughty.
If the second means "He has been being naughty", then the first means "It has been being hot".
They aren't expressed in the continuous tense; but the meaning is generally continuous in both.
If the meaning is not continuous, you could have the following sensible conversation:
A: Phew. It's been hot today!
A: Between 2.30 and 3pm.
But even the simple past tense implies some degree of continuity with these sentences. "It was hot today" generally doesn't mean that at one time today it became hot for a moment then wasn't again.
The problem with the way this point is expressed (and perhaps others - I haven't bothered reading them all) is that the tense is the way a sentence is written - not what it means.
"I go to London tomorrow" is in the present tense. "I'm going to London tomorrow" is in the present progressive.
Along with "I will go to London tomorrow", they all have future meaning, but they're not all in the "future tense".