Art of the Small was a radical Force technique. By narrowing their focus, a Force user could essentially shrink their presence in the Force to a microscopic size. While in this state, the user could operate molecules in any way they wanted, turning them into something completely different.
With the power to alter things at a molecular level, a Force-user could have limitless uses for such a technique. Vergere, the Jedi Knight who named it, used her powers to give her tears healing properties, which helped Mara Jade Skywalker in combating the Coomb Spores she was infected with. She managed to teach the Art to Jacen Solo and Cilghal. Onimi, jester to Shimrra Jamaane, also had this ability, but his level of control was much greater than Vergere's. He could produce toxins and manipulate the electrical current around him, allowing him to control Shimrra and become the true Supreme Overlord of the Yuuzhan Vong.
As demonstrated by Vergere, the Art could be employed to conceal one's presence in the Force or outright render them invisible. Thus, it was not only a unique method for Force healing, but it was also another manner of Force concealment or Force camouflage. This may very well have been the technique used by Alema Rar, Numa Rar, and Lumiya to hide their presence in the Force.
i also believe that a power such as this could be beneficial to many jedi, for those that know its history ans uses, it would be a very useful power to any jedi who utilizes it.