Unfortunately, there is nothing useful to share there. No matter how hard I tightened the clamps, the swivel still worked. In frustration I even tried to drill a nut to the telescope column but all that achieved was a major hydraulic spill (never occurred to me there must be something inside that makes the telescope work). I eventually gave up and built a proper simrig instead.
Btw, I’ve seen someone hook the armrests to their desk to fight the swivel but I haven’t tried that.