Would that really save much time/effort?
Alt + Printscreen with the visualizer open and then on paste.pics Ctrl+V
Even having to type in a filename to save would take me longer...
It's really not a lot of code to do and would save only the framebuffer to file. Just a nice to have feature, like we did it for OC.
PS: Also i see it as a task for newcomers, so they can learn the visualiser structure.