Rwake901......Typically, many find the rear track bar to be the most helpful improvement, but you've done that. Personally, I think the aftermarket steering stabilizer's are more about giving people a warm and fuzzy feeling in case there is a blow out, but does little to solve wander issues. This post has impressed me because many have admitted that the stabilizer didn't help. Most won't admit that after spending the money.
I added a Safe-T-Plus stabilizer to my previous DP and hated it. Just made it harder to steer (turn the wheel). I removed it and replaced it with the Blue Ox TruCenter. The TruCenter is very pricey, but was great for correcting wind push and road crown. I didn't have wander issues, so I couldn't tell you if it will help that.
I see your coach is a 2014. Have you previously owned a Class A motor home prior to this one? The reason I ask....many new owners of large Class A motor homes tend to drive them like a car. They're constantly steering to stay in the center of the lane. Cars will stay there with subtle movements, a motor home takes more input.
If you're new to a Class A, try steering toward a point farther down road, rather than looking at a spot directly in front of you. It will keep you from making s
Lastly.....next time you drive the coach, take the steering wheel and tilt it all the way forward and drive that way for a few minutes. You'll find you'll be compensating like crazy. With that said, move the steering wheel as far down as it will go and still be comfortable. You'll be less likely to over steer/wander.