A good feature to have is inverted image color feature, especially for BW bitmap’s, will make it easier if light/dark themes are used and/or set custom palette for 1 bit bitmap’s is better, if alternate palette is provided to ignore the one in the bitmap and transparent state as variable set in software.
Another good feature is to add a gradient on a 1bit bitmap using the bitmap as a mask? 
Good idea! Once v9 is released we can add support for rendering to 1 bit, and all these magic can be considered.
Let’s get back to this in 1-2 month.