rear tires unloading

I would tighten the front shocks extension. Slow it down so it tops out softer/later. If you don’t have adjustable shocks in front, you can lower the ride height. Which makes it travel farther, taking longer. If you can’t, is the car throwing the rear axle down HARD? You might slow that down by tightening up the rear extension. If all else fails you could soften the compression in the rear to limit the bounce.