I have a 2018 Southwind 36P and previously owned 3 RVs on the F53 chassis.
I have done no other upgrades other than the cheap handling fix, and I have never experienced
uncomfortable sway. I run on a lot of windy mountain roads and the 36P holds the turns pretty good.
The CHF is free and takes about an hour, there are several threads and u-tube videos about it.
I would try it first, then move up to better options if you do not get the ride you expect, the
new sway bars and shocks should obviously make a big difference, but so far I have not tried them.