Another issue that I could notice is that when on interactive rendering, every time I have a mouse click, the render reloads on the VFB. Even when I'm just passing through channels or layers on material editor (without change anything) it reloads the VFB.
Also when rendering a region area on the interactive and change a parameter on the menus or material editor, the whole render reloads, not only the region box. It should reload only the region area I think.