Would love to see this. It’s one of the most common needs in page builders, and one of the critical missing features in Gutenberg. font-family is definitely something that needs to change on a per block basis. For example: your default h2 styling is serif, but you want it to be sans-serif for a particular block, pattern, or template. I think the best interface would be if a global option defines what fonts are available, and then be able to choose one of those in individual block settings. The typefaces available in Editor Plus might need to be a manual list of values (font-family names or var() names), so that we can use fonts from the theme. This should definitely not be limited to Google Fonts.
