Koni shocks improve ride quality but minimally affect body roll. Sway bars are what reduce roll. Check if your Fleetwood has sway bars - adding them will make the biggest handling difference.
Everything RV owners need to know about the Ford 6.8L Triton V10 engine including common problems and solutions.
If suspension and frame are square but body sits low on one side, the issue is body mounts. Check for loose bolts, failed rubber isolators, or manufacturing variance. Body shims can correct this. Since its a 2021, contact Jayco about warranty coverage.
Rear sway bar bushing replacement straightforward with basic tools. Consider polyurethane upgrade. Replace end links if worn while accessible.