The Cross & Triangle

The symbol of the Golden Dawn is a red calvary cross above a white triangle, often, but not always, shown upon a black background. This is a very evocative image, which means different things to different people, but what does it mean for the Golden Dawn as a whole?
The Neophyte Ceremony tells us the following about it:

"The Red Cross above the White Triangle is an Image of Him Who was unfolded in the Light."

Another section states:

"Two contending Forces and one which unites them eternally. Two basal angles of the triangle and one which forms the apex. Such is the origin of Creation - it is the Triad of Life."

Z3 refers to "the White Triangle of the Three Supernals formulating in Darkness" and states that the Candidate "may bear that potent and sublime symbol as a link with his Higher Self and as an aid in searching out the forces of the Divine Light"
Z1 states:

"The Symbols upon the Altar represent the Forces and Manifestation of the Divine Light, concentrated in the White Triangle of the Three Supernals as the synthesis; wherefore, upon this sacred and sumblime Symbol, is the obligation of the Neophyte taken as calling therein to witness the Forces of the Divine Light.
The Red Cross of Tiphareth (to which the Grade of 5=6 is referred) is here placed above the White Triangle, not as dominating it, but as bringing it down and manifesting it unto the Outer Order; as though the Crucified One, having raised the symbol of self-sacrifice, had thus touched and brought into action in matter, the Divine Triad of Light."

This clearly refers to an invocation of the Light of the Supernal Triad into the manifestation of the Outer Order, as can be seen in this image:

Of course, the triangle may not be placed as shown above, but may encompass Yesod and Malkuth also, but the above format keeps the form of the triangle consistent with the form of the Tree itself. Perhaps it could be seen to show the delicate link between the Water of Practicus and the Fire of Philosophus, and perhaps it is used to balance these two contending forces with the one that unites them eternally in Tiphareth (symbolic of Air). This also correlates with the placement of the Triangle on the Tree in the Admission Badge for Portal (Hiereus lamen).