I've been using the PPT for years - it works perfectly for maintaining target temp on both polaris and vega.  For navi, it works fine if you want to control for junction temp.  The problem is that mem temp is usually the concern, so i have to set the target junction temp really low, but when ambient drops, the fans slow down and mem temp skyrockets again. There's a bit to select which sensor you're targeting (edge, junc, or mem) but it doesn't seem to work in current drivers