you might try on the more general suspension forum, since there's not a lot of traffic in here and very few of the hybrids used the mag ride. I think most were sold as tahoe's. they seemed to lean more towards economy, so gm went further with the weight savings and aero. no idea what kinda power it takes to run these mag shocks, but it does seem odd to put them on a half electric truck when shooting for best mileage.
also just from my experience, the rear shocks have a more noticeable affect on passengers felt stiffness than the fronts. I've spent a lot of time messing with adjustable coil overs on other cars. so maybe just toss two 2 new oem rear shocks on to see if you notice any real difference first? that is if you're doing this work yourself. if having a shop do it, yeah might be cheaper and easier to have it all done at the same time. I'm worry is you do it all and notice no real improvement.
other think I thought about was tires, you'd be amazed how much a new set of tires geared towards what you want from them can make or break a car's ride. so these denali's always list a 20 in chrome wheel as standard. my truck didn't have them when I got it, which seemed weird. so lots of searching I caught an * at the bottomed of an rpo sheet that showed a different set of wheels as a no cost option, the example giving was owner lives on a dirt or gravel road and wants a more compliant Tire, turns out I had that rpo code on mine. they are the same overall height tire but a 17in rim for more sidewall. if you're not happy with the ride after shocks, it might be a next step for you, something with a softer tire with more side wall. you can search for the same overall height, or just go different and adjust the speedo with hptuners.
