While Gaussian Blur is not a Blur type that really benefits much from linear sampling, it can be used for a slight quality and gpu usage reduction. However for Area and Directional Blur there is a better alternative: Dual Filtering Blur. And as with all other currently implement Linear versions of Blur, only Area and Directional Blur are supported.
This type of Gaussian Blur also has the loading hitch that exists in normal Gaussian Blur.
Related: #45, #6