Yes, its a little difficult but its worth it.
It takes some work to accustomed to and is more complicated than the super-easy sprite commands in GLB. However, once you get used to it you'll probably do everything using polyvectors. If you're drawing a lot of sprites it can be faster than sprite commands in GLB because you will tend to use the same texture to draw multiple sprites in the same draw call.
It can be used to replace the stretchsprite / usescreen method. I'm not sure how much faster or slower it is without making a test program but it looks better.
There are examples of how people have made screen scaling here on the forum, like
Z-Project.
You may want to get your hands on a texture packer and write your own importing routine to speed things along. I use a commercial texture packer and wrote a little proggy to import the sprites into GLB by generating code to name the sprites I can paste straight into my apps. Its very quick that way.