with the extension I use the soft center avia cam for roll and no center avia cam for pitch. I use the heaviest springs cranked down as tight as I can make them. As long as you are using a virpil grip (lightweight) it has zero issue returning to center.
If you are using a thrustmaster grip I would recommend playing around with it. you will definitely want the heavy springs, Cam choice is gonna be trial and error tho. On an extension a thrustmaster grip is honestly too heavy for the cams/springs provided, still works, but the stick can’t quite return to center with the extension, moment arm is too long.