SQ and QS were cut from a matrix-encoded master tape that was stereo for all (cutting) intents and purposes, so the cutting was done on the same equipment as regular stereo LPs. This was a big part of CBS' push to sell the format to all parts of the music ecosystem, from mixing and mastering houses to the end consumer, that SQ was in every way compatible with stereo and didn't require any new equipment if you didn't want to buy it.
I can't speak for the cutting of QS LPs but for SQ the only concession that CBS made (on their own albums anyway) is that they cut them with as close to zero compression or EQ in the mastering stage, because they worried that the analog components that performed these tasks could have a detrimental effect on the phase encoding. So what you hear on those SQ LPs from their labels (Columbia, Epic, Blue Sky, PIR etc.) is basically the '70s version of today's "flat transfer," and to be honest you can kind of tell - a lot of SQ LPs sound kind of flat and lifeless, because they haven't had the golden ears of a disc mastering engineer able to do anything to them.
As furui says, CD-4 required all new equipment and mastering - a new vinyl compound and half-speed mastering to get the carrier signal properly cut on vinyl (and reduce distortion) and also a brand new cutting lathe, originally an enormous one from JVC Japan and later a US-designed model circa 1975 that I think was called the Quadulator. The main difference between CD-4 cutting and SQ/QS was that with CD-4 there was no intermediate equivalent of the SQ matrix-encoded stereo master tape to cut from, which is part of why the new lathe was necessary - it had a four-channel input you'd feed the discrete master to, and then cut it directly to a CD-4 modulated disc that was then used to make the stampers for LP production. The other difference is that CD-4 LPs (at least the ones cut at the JVC Cutting Center in Hollywood) are definitely mastered in the traditional sense - they all exhibit obvious and noticeable EQ differences from the recent Rhino Quadio discs, which are almost certainly flat transfers from the quad master tapes.
