QDS1 ? Well no but I did utilize something similar . Sansui QSD2 .I don,t know with what Decoder you were using
But I have played them with QDS1 and Surround Master
Plus the same speakers front and back
And found them full surround but a soft surround
Not to many solo,s in the rear
If you played them in a basic QS decoder the surround may be less.
And no I'm sorry , but I never found 'em too glory surround showcase for QS. . Nothing at all like the "Dan's" nor Joe Walsh 's TSYD , TPYG.
Perhaps ABC/IMPULSE/DUNHILL quad discs were somehow Encoded with a Bad Encoder (sometimes) . Could xplain the inconsistency with some of their QS matrix product.
Project 3 and Ovation never seemed to encounter bad encodes from my observations.