There is this sentence:
There are several parts to this problem, the most important (part) being that many of the learners find it rather boring.
I would like to know if the phrase in bold-faced type is short form of a clause or something.
If yes, what is the original form of the sentence?
To me, it sounds like the original form is "the most important of which is that..."
As in:
The man who lives next door = the man living next door
Does it follow the same rule or is the case different?
And, can we simply use the verb "is" instead and say "the most important is that ..."
If yes, what is the difference between "...being that..." and "...is that..." in the sentence? Is it only a matter of style?