Edifice III (Roman numeral “3”) is mostly in ruins. I did not feel anything from it. And unfortunately I did not see or know about Lintel X (“10”) described below.
According to YAXCHILAN: The Design Of A Ceremonial City by Carolyn E. Tate, Copyright 1992, ISBN 0-292-77041-3, Page 154, Teobert Maler rediscovered Edifice III in 1897. INAH subsequently cleared the temple, which resembles a small platform because the walls contain much rubble. Maler found 2 lintels in the rubble: a presently unnumbered lintel and Lintel X (“10”). Lintel X (“10”) is the latest dated Lintel at Yaxchilan, approximately 810 A.D.