In the Insights to the Daf, The Yefei Einayim asks a question on the GR"A cited in Kol Eliyahu. The question presupposes that that Amos by which the Paroches was measured were 6-Tefachim Amos as opposed to 5-Tefachim Amos. Therefore, an alternate approach to the GR"A is offered.
However, the Mefaresh clearly understands that even the Amos of the (Binyan) [Paroches] are 5-Tefach Amos, since he objects to the understanding that each Paroches was a Tefach wide since this would leave only 3 Tefachim between them. According to this, the question of the Yefei Einyim does not begin, and the Kol Eliyahu can be understood as it is written.
Moshie Cohen, Har Nof, Israel
The Mefaresh is addressing the thickness of the Paroches, which is not dependent on the length and width of the opening at the doorway. There is no reason for that Amah not to be measured by the Amah of Kelim, which is five Tefachim.
However, the Gra is discussing the width and length of the Paroches, dimensions which are clearly dependent on the size of the doorway that the Paroches covers. The dimensions of the doorway clearly should be determined by the Amah of the Binyan, which is 6 Tefachim.
Best wishes,
Mordecai Kornfeld