I agree with you that the more lines that are covered are better than leaving one hanging.  The books are quite informative as are the other Quality Chess books I have...Marin's English series come to mind as superb.  I've been checking this volume from Kotronias and find that one should be aware that transpositions are highly possible.  I've been using Chess Opening Explorer and it has found a few transpositions that Kotronias and the editors did not notice.  If I find any that are noteworthy I will try to post them here for those that are interested.

In volume II of Kotronias' King's Indian Mar del Plata books, he suggests two continuations for black on pages 59 and 60.  The following position occurs in a note to white's main move 16.Bd3 on page 59.  The note in question begins with 16.f3 Qd7 17.Bd3 Nh5 18.g3.  Here, Kotronias suggests black continue with 18...Rfa8 which he states is equal after black plays 24...Qxf5.  However, I find it difficult to agree with this evaluation after 25.g4.  Also, on page 60 in a note to black's main move, 16...Qa8, he suggests that 16...Qd7 might be better continuing with 17.f3 Nh5 18.g3 which produces the same position but here he suggests that 18...f5 is the way forward which I think might be best.

Perhaps he missed this transposition.