Firstly, I’d like to kindly request not to mark this question as a duplicate of previous SE question without first reading this, because the approach is different and the previously given answers are merely incorrect.
I found this information in VoyagerEssay.pdf from Burt Rutans website.
EDIT: I am putting this possibly redundant info with the hope it might help better clarify the problem as suggested.
From Burt's own notes.
The range of an aircraft is determined by three basic criteria: its propulsion efficiency, its weight and its aerodynamic efficiency. I had to make major improvements in one or more of these areas in order to build an aircraft that could fly more than twice as far as any previous flight.
Please see "breguet-range-equation" for more info. And this range equation suggests us the range of an airplane is exponentially sensitive to the initial and final weight ratios; and linearly sensitive to L/D and total propulsive efficiency eta.
And as the per the same source, this configuration was chosen to achieve higher structural efficiency.
The primary reason we were able to double the old record related to our success in weight control. By using a new, unusual configuration we could place a large amount of fuel at three span-wise locations: the fuselage and two large booms at 30% of the distance out to the wing-tips. A very light main wing and canard wing provided just the amount of structural support for this large fuel mass. The two wings supported the fuel-laden booms via their bending stiffness without depending on the torsional stiffness of a single slender wing. This was Voyager’s secret to success. Its graphite composite structure weighed only nine percent of the take-off weight. The fuel consisted of 73% of the take-off weight. This phenomenal weight performance was the main reason we were able to achieve our goal of true global range.
And of course in return traded off aerodynamic efficiency.
Regarding aerodynamic efficiency, I was unable to achieve a result as high as a typical sailplane since I was forced to use the unusual configuration
In this John Roncz presentation, he mentioned this configuration was to solve the problems of having high inertia fuel booms, [~18 mins] but without any specific note on how it resolves into a canard. As per Mr. Roncz, he appears to suggest this minimizes the bending stresses of the booms. (Please correct me if Im wrong) and note from Burt appear to suggest the config was selected to minimize wing torsional loads.
Can any of you please provide me with an explanation as to why the canard configuration ideally could be more beneficial for this design?
My argument is if he had chosen the second config shown below, he would have gained BOTH structural benefits of canard plus aerodynamic benefits of conventional config.
In my eyes, this is an even better win-win solution but most certainly too good to be true; hence my question.
If possible I would love to see some quantitative answer rather than qualitative but any constructive answer is more than very welcome.