There are a number of review articles on google and YouTube about these supports.

They tend not to have the adjustment range as footstools. [br]They look as if they set the neck to about 40 to to degrees. [br]The main difference in use is both feet flat on the floor and the body planes can be kept square. [br]No twisting on the spine etc. [br]Think mine is leaning the head to see the hand and fret positions which is heavy on the neck.

radical option is to switch to left hand every 15 minutes.

does that balance both sides or wreck both sides