In your posting, you say:
"Internal encoding (where the front phase reference is bypassed) is what you get if you use only one decoder to encode the back channels. That version randomizes the phase front front to back, which helps prevent cancellations in the encode process."
There is no such thing as a Front Phase Reference in the SQ encoder. The Rears are phase shifted and mixed with no reference to the fronts at all.
Also, i'm afraid your wrong when you say:
"QS uses phase shifts as does Dolby Surround to prevent cancellation in the encoder, but not as part of the actual encode process. They should not be considered to be phase matrix's. If you ignore phase of the decoded outputs phase shifting for those systems is unnecessary. The original Dolby surround is in fact the same as QS with only Cb encoded."
The phase shifts in both SQ & QS are part of the encoding, and NOTHING to do with preventing cancellation in the encoder. I suggest you do some investigation on the way the phase matrix's actually work, and the first thing to do is ignore the large amount of incorrect information on that website.
If you do a search elsewhere here, i recently had to correct someone else's belief that Dolby Surround was based on QS. It was stolen from SQ. Find that posting, and look at the equations i supplied. There's also enough information on the internet regarding this.
By the way, in Dolby Surround, Cb wasn't encoded at all,. it was created in the decoder:
Cb = 0.707 Rt + 0.707 Lt