I expect GM is as terrified as any other manufacturer of lawsuits. But your recounting of fear of oversteer might be over-simplified if the 1st Gen straight axle Corvair's propensity to flip over somehow found any application to stab bars on full frame RWD Front Engine design. Sounds like comparing apples and -- toenails.
I'm more after usable takeaways than anything else, and I can clean up the above quickly into usable bullets. From first experiments 30 years ago with an HA front and GM 'cop option' rear bar on an '82 Park Ave. Electra, I progressed to the severe lockdown affect of an F- front and HO rear on my SS. But, it's just a garage queen, and not that enjoyable after 3 hours on an interstate. I've read your prior reply on another thread regarding optimal setup for my 'new' '96 FWB, and I absorbed pretty much there as also above.
For my desired ride somewhere between the 'the blu-hair undead' FE-1 and full NASCAR I'm pretty much siding with the following based on my experience with my last Fleetwood. On that one I had transferred the stock bars off my SS combined with used SS coils and Bilsteins. The car still plowed more than my liking, but much improved responsiveness of course with less pushing. So I first tried adding the Cady rear bar to the SS, = meh. Then, putting 2 SS bars on back was quite a wake-up! It provided very gratifying control to reduce pushing and plowing. I noticed of course at a certain point it could tip into oversteer if not careful. More reasons not to drive tired or drunk I say. Win-win.
With my current Cady I'm pretty settled that regular SS bars will satisfy my base setup without having to buy anything aftermarket. I was offered an F- front but declined gracefully. And, instead of 2 rear SS rear bars I'm going to try an SS bar combined with the current FE-1 rear. Of course I've got no math to calculate the net positive delta as compared to the GM law of -1/8". I can't believe the stresses are simple arithmetic, more likely progressively exponential or geometric or something.
In any case, the wimpy oem Cady bar and nicely sized SS bar will be a good fit considering my general satisfaction with 2 SS rear bars previously. I already have the front and rear SS bars waiting, now just $750 more to go for KONIs and poly LCAs. And maybe a little frame gusseting. And Airlift 1000s again. And maybe a 1/3-1/2 coil off the fronts, you know for rake and 50# harder spring rate. And----
\'96SS SOB: SSRI, Herter Tune, Tri-Y II, , 3000 Edge, F/HO bars, METCO extendeds with CV MMC, Bilsteins, currently Vredestein Ultrac Sessanta (315/35 rear). Finally, wait for it... LT-4 knock module!
\'96FWB BUW-Butt Ugly White: PCMPerformance tune, HDFA w/ swissed filter, 1/2 SLP s.s. catback with H- and Flow Super 50s, oem opti rebuilt 3 times, SS Bars, METCO LCA, Airlift 1000, Monroe SS, PowerTrax No-Slip, CTS wheels with +1 rubber. Finally, yes again... LT-4 knock module!