It would be great if we could set a default font at the brand settings level. This initially came up while trying to see if I could change the font in the default modules to a sans-serif font. I learned this is not possible, even when cloning the default module so it's editable.
It may possible for people with more expertise in source code editing, but even a simple option to select serif vs sans-serif at the brand level would make the default modules appear more consistent with brands which use one or the other.