The LTSCALE Switch is an ARX utility that automatically saves the LTSCALE value when switching from the Model Space to Paper Space, then sets it to 1. It restores the value when you switch back to Model Space even if you quit the editing session within a Paper Space tab. All that in real time.
This utility solves one major problem yet unsolved when working with the Paper Space: It is hard to easily get uniform linetype scale. Setting the PSLTSCALE variable to 1 (ON) forces you to set the LTSCALE variable to 1. This is somehow annoying because you must pop the original LTSCALE value when you switch back to the Model Space.