Backround Image Alpha Operation

I'm not sure how most people use background images but I often use them in front to mask visible areas for unconventional displays. The masks are always produced in black and white. When it comes to previewing its usually just a matter of settting it to multiply. In the view port however, I always need to make a version with alpha in Photoshop.

Blend modes would also be great but I'm reminded that the ability to calculate an alpha aready exists in the Texture panel.

In addition the option to disable visibilty per viewport is missing (without disabling all overlays) but existed in 2.79.