Using separate .mkfont files as re-usable libraries
There is currently no way to import an MkFont file into another, by design : you can copy/paste-in-place glyphs from an open document to another.
What I tend to do is keep sets of glyphs in separate .mkfont files that I use as kind-of ‘external libraries’, pasting what I need from them to another .mkfont file using the / manipulation.
This is especially useful if, for example, you have a set of recurring characters that you end up including in different fonts; i.e controller icons and the like.
Using non-exported ligatures as re-usable named components
Since components work by importing existing glyphs, it comes in handy to create ligatures with human-readable names (like you would with layers in a tidy photoshop document), set them to not be exported along with the font, and voila, you got yourself a component library!
This is especially useful when working with complex icon sets, or when naming artboards as Unicode value isn’t an option. The
Composite icon font guide is a good demonstration of that.
WORK IN PROGRESS.
Come back later (～￣▽￣)～