BTW, to answer the underlying question, I don't know what kind of strings Segovia liked or why, only that he famously endorsed Augustine ones. Last time I used a pack, it still had his endorsement on the inside, even though he's been dead nearly 30 years. I'd like to believe he actually preferred and used the strings he endorsed for the majority of his career. He's publically claimed that he preferred these:
http://classicalguitarmagazine.com/from ... -the-road/
“I practice two hours with the same strings, and already they do not sound very good. Absolutely. It is a case of ‘Very well, I am going to change the second and the first’. ” In spite of that he still used Augustine strings. “Many others have taken up the possibilities, of making nylon. But it is the same situation. I have no obligation with Augustine. 1 never accept any obligation, either with strings or with the guitar. No, no, never. But 1 have to admit the truth: that the best strings are Augustine.”
As to the question of whether or not he used a B string for his high E, I'll venture my answer of "no". Just watch this close up of him playing. Seems clear (at least to my eye) that his 2nd string is fatter than his 1st one:
Segovia performed publically constantly during his lifetime, and he taught other students both privately and in large master classes. If he consistently used paired gauge strings for his two highest ones I think this would probably be common knowledge. Its also likely that Augustine would have issued a "Segovia" set taking this into account. So far as I know neither of these things have happened.
On the topic of tonality, Segovia we'll recall, started playing in an era of gut strings. High E guitar gut string is notoriously weak and thin sounding, explaining (for example) why Tarrega wrote many of his pieces with the melody on the B string (eg Recuerdos Del Alhambra). Hard to say to what extent this might have influenced Segovia's later choice of strings, or positions, but its certainly plausible that he adopted the rule of trying to avoid the 1st string when he could.